diff --git a/Jenkinsfile b/Jenkinsfile
index 3aef5503..09ed25d2 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -26,7 +26,9 @@ node('factory2'){
         stage('Pre Setup Node'){
             // Install EPEL and the SCLs repo
             onmyduffynode 'yum -y install epel-release yum-config-manager centos-release-scl && yum-config-manager --enable rhel-server-rhscl-7-rpms'
-            onmyduffynode 'yum -y install python27 python-devel rh-python36 @development krb5-devel openssl-devel libffi-devel swig createrepo_c'
+            onmyduffynode 'yum -y install python27 python-devel rh-python36 @development krb5-devel openssl-devel libffi-devel swig createrepo_c cairo-gobject-devel gobject-introspection-devel'
+            // Remove this once it's available in the official repos
+            onmyduffynode 'yum -y install https://kojipkgs.fedoraproject.org//packages/libmodulemd/1.0.4/1.fc26/x86_64/libmodulemd-1.0.4-1.fc26.x86_64.rpm'
             // Update pip and setuptools and install tox in the SCL environment
             onmyduffynode 'scl enable python27 \'pip install --upgrade pip setuptools tox\''
             onmyduffynode 'scl enable rh-python36 \'pip install --upgrade pip setuptools tox\''
diff --git a/Vagrantfile b/Vagrantfile
index d5716db8..b1789e49 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -21,6 +21,7 @@ $script = <<SCRIPT
         python-devel \
         python-docutils \
         python-flask \
+        python-gobject-base \
         python-m2ext \
         python-mock \
         python-qpid \
@@ -33,7 +34,8 @@ $script = <<SCRIPT
         redhat-rpm-config \
         rpm-build \
         swig \
-        systemd-devel
+        systemd-devel \
+        https://kojipkgs.fedoraproject.org//packages/libmodulemd/1.0.4/1.fc26/x86_64/libmodulemd-1.0.4-1.fc26.x86_64.rpm
     cd /opt/module_build_service
     python setup.py develop
     python setup.py egg_info
diff --git a/module_build_service/builder/CoprModuleBuilder.py b/module_build_service/builder/CoprModuleBuilder.py
index bbb6e842..42e43a05 100644
--- a/module_build_service/builder/CoprModuleBuilder.py
+++ b/module_build_service/builder/CoprModuleBuilder.py
@@ -84,12 +84,16 @@ class CoprModuleBuilder(GenericBuilder):
         self._create_module_safe()
         mmd = self.module.mmd()
 
+        # Even though get_buildrequires returns a dictionary with the values as lists, there will
+        # always be a single item in the list after MBS processes it
+        buildrequires_d = {name: dep.get()[0]
+                           for name, dep in mmd.get_dependencies()[0].get_buildrequires().items()}
         buildrequires = ["@{}:{}/{}".format(n, s, "buildroot")
-                         for n, s in mmd.buildrequires.items()]
+                         for n, s in buildrequires_d.items()]
 
-        buildroot_profile = mmd.profiles.get("buildroot")
+        buildroot_profile = mmd.get_profiles().get("buildroot")
         if buildroot_profile:
-            buildrequires.extend(buildroot_profile.rpms)
+            buildrequires.extend(buildroot_profile.get_rpms())
 
         self._update_chroot(packages=buildrequires)
 
@@ -150,9 +154,9 @@ class CoprModuleBuilder(GenericBuilder):
         # Write module's name, stream and version into the modulemd file
         # so Copr can parse it from there
         mmd = self.module.mmd()
-        mmd.name = str(self.module.name)
-        mmd.stream = str(self.module.stream)
-        mmd.version = int(self.module.version)
+        mmd.set_name(str(self.module.name))
+        mmd.set_stream(str(self.module.stream))
+        mmd.set_version(int(self.module.version))
 
         modulemd = tempfile.mktemp()
         mmd.dump(modulemd)
diff --git a/module_build_service/builder/KojiModuleBuilder.py b/module_build_service/builder/KojiModuleBuilder.py
index 7d9fd26e..c64f16cd 100644
--- a/module_build_service/builder/KojiModuleBuilder.py
+++ b/module_build_service/builder/KojiModuleBuilder.py
@@ -238,7 +238,7 @@ class KojiModuleBuilder(GenericBuilder):
         # module-build-macros to conflict with these filtered RPMs to ensure
         # they won't be installed to buildroot.
         filter_conflicts = ""
-        for req_name, req_data in mmd.xmd["mbs"]["buildrequires"].items():
+        for req_name, req_data in mmd.get_xmd()["mbs"]["buildrequires"].items():
             if req_data["filtered_rpms"]:
                 filter_conflicts += "# Filtered rpms from %s module:\n" % (
                     req_name)
@@ -300,8 +300,9 @@ chmod 644 %buildroot/%_sysconfdir/rpm/macros.zz-modules
            filter_conflicts=filter_conflicts)
 
         modulemd_macros = ""
-        if mmd.buildopts and mmd.buildopts.rpms:
-            modulemd_macros = mmd.buildopts.rpms.macros
+        rpm_buildopts = mmd.get_rpm_buildopts()
+        if rpm_buildopts:
+            modulemd_macros = rpm_buildopts.get('macros')
 
         macros_content = """
 
diff --git a/module_build_service/builder/MockModuleBuilder.py b/module_build_service/builder/MockModuleBuilder.py
index 0ebb4765..9e8943bf 100644
--- a/module_build_service/builder/MockModuleBuilder.py
+++ b/module_build_service/builder/MockModuleBuilder.py
@@ -26,12 +26,14 @@ import logging
 import os
 import koji
 import kobo.rpmlib
-import modulemd
 import pipes
 import platform
 import re
 import threading
 
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 from module_build_service import conf, log
 import module_build_service.scm
 import module_build_service.utils
@@ -182,17 +184,20 @@ class MockModuleBuilder(GenericBuilder):
             if m1.last_batch_id() == m1.batch:
                 # If RPM is filtered-out, do not add it to artifacts list.
                 nvr = kobo.rpmlib.parse_nvr(rpm)
-                if nvr["name"] in m1_mmd.filter.rpms:
+                if nvr["name"] in m1_mmd.get_rpm_filter().get():
                     continue
 
             pkglist_f.write(rpm + '\n')
             rpm = rpm[:-len(".rpm")]
-            m1_mmd.artifacts.add_rpm(str(rpm))
+            component = Modulemd.ComponentRpm()
+            component.set_name(str(rpm))
+            component.set_rationale('none')
+            m1_mmd.add_rpm_component(component)
 
         pkglist_f.close()
 
         mmd_path = os.path.join(path, "modules.yaml")
-        modulemd.dump_all(mmd_path, [m1_mmd])
+        m1_mmd.dump(mmd_path)
 
         # Generate repo and inject modules.yaml there.
         execute_cmd(['/usr/bin/createrepo_c', '--pkglist', pkglist, path])
diff --git a/module_build_service/migrations/versions/9ca1c166f426_contexts.py b/module_build_service/migrations/versions/9ca1c166f426_contexts.py
index b3087247..4b0b3729 100644
--- a/module_build_service/migrations/versions/9ca1c166f426_contexts.py
+++ b/module_build_service/migrations/versions/9ca1c166f426_contexts.py
@@ -14,7 +14,9 @@ from alembic import op
 import sqlalchemy as sa
 
 # Data migration imports
-import modulemd
+import gi
+gi.require_version('Modulemd', '1.0')
+from gi.repository import Modulemd
 import hashlib
 import json
 from collections import OrderedDict
@@ -40,22 +42,23 @@ def upgrade():
     for build in connection.execute(modulebuild.select()):
         if not build.modulemd:
             continue
-        mmd = modulemd.ModuleMetadata()
         try:
-            mmd.loads(build.modulemd)
+            mmd = Modulemd.Module().new_from_string(build.modulemd)
+            mmd.upgrade()
         except Exception:
             # If the modulemd isn't parseable then skip this build
             continue
 
-        mbs_xmd = mmd.xmd.get('mbs', {})
+        mbs_xmd = mmd.get_xmd().get('mbs', {})
         contexts = {}
         for property_name in ['buildrequires', 'requires']:
             # It's possible this module build was built before MBS filled out xmd or before MBS
-            # filled out the requires in xmd
-            if property_name not in mbs_xmd:
+            # filled out the requires in xmd. We also have to use keys because GLib.Variant
+            # doesn't support `in` directly.
+            if property_name not in mbs_xmd.keys():
                 break
-            mmd_property = getattr(mmd, property_name)
-            if mbs_xmd[property_name].keys() != mmd_property.keys():
+            mmd_property = getattr(mmd.get_dependencies()[0], 'get_{0}'.format(property_name))()
+            if set(mbs_xmd[property_name].keys()) != set(mmd_property.keys()):
                 break
             mmd_formatted_property = {
                 dep: info['ref'] for dep, info in mbs_xmd[property_name].items()}
diff --git a/module_build_service/models.py b/module_build_service/models.py
index 42866308..dc0e38a2 100644
--- a/module_build_service/models.py
+++ b/module_build_service/models.py
@@ -34,12 +34,13 @@ import hashlib
 import sqlalchemy
 from sqlalchemy.orm import validates, scoped_session, sessionmaker
 from flask import has_app_context
-import modulemd as _modulemd
-
 from module_build_service import db, log, get_url_for, app, conf
 import module_build_service.messaging
 
 from sqlalchemy.orm import lazyload
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 
 # Just like koji.BUILD_STATES, except our own codes for modules.
 BUILD_STATES = {
@@ -241,9 +242,9 @@ class ModuleBuild(MBSBase):
             ]
 
     def mmd(self):
-        mmd = _modulemd.ModuleMetadata()
         try:
-            mmd.loads(self.modulemd)
+            mmd = Modulemd.Module().new_from_string(self.modulemd)
+            mmd.upgrade()
         except Exception:
             raise ValueError("Invalid modulemd")
         return mmd
@@ -281,14 +282,18 @@ class ModuleBuild(MBSBase):
 
     @staticmethod
     def contexts_from_mmd(mmd_str):
-        mmd = _modulemd.ModuleMetadata()
-        mmd.loads(mmd_str)
-        mbs_xmd = mmd.xmd.get('mbs', {})
+        try:
+            mmd = Modulemd.Module().new_from_string(mmd_str)
+            mmd.upgrade()
+        except Exception:
+            raise ValueError("Invalid modulemd")
+        mbs_xmd = mmd.get_xmd().get('mbs', {})
         rv = []
         for property_name in ['buildrequires', 'requires']:
-            if property_name not in mbs_xmd:
+            # We have to use keys because GLib.Variant doesn't support `in` directly.
+            if property_name not in mbs_xmd.keys():
                 raise ValueError('The module\'s modulemd hasn\'t been formatted by MBS')
-            mmd_property = getattr(mmd, property_name)
+            mmd_property = getattr(mmd.get_dependencies()[0], 'get_{0}'.format(property_name))()
             if set(mbs_xmd[property_name].keys()) != set(mmd_property.keys()):
                 raise ValueError('The dependencies.{0} section of the modulemd doesn\'t match '
                                  'what is in xmd'.format(property_name))
diff --git a/module_build_service/resolver/PDCResolver.py b/module_build_service/resolver/PDCResolver.py
index bbf3abaa..9b274d79 100644
--- a/module_build_service/resolver/PDCResolver.py
+++ b/module_build_service/resolver/PDCResolver.py
@@ -26,7 +26,9 @@
 
 """PDC handler functions."""
 
-import modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 import pdc_client
 from module_build_service import db
 from module_build_service import models
@@ -99,7 +101,7 @@ class PDCResolver(GenericResolver):
             return True
 
         def is_modulemd(data):
-            return isinstance(data, modulemd.ModuleMetadata)
+            return isinstance(data, Modulemd.Module)
 
         def is_module_str(data):
             return isinstance(data, six.string_types)
@@ -110,14 +112,11 @@ class PDCResolver(GenericResolver):
             result = self._variant_dict_from_str(data)
 
         elif is_modulemd(data):
-            result = {'variant_id': data.name}
-            # Check if this is an old modulemd that doesn't use the new nomenclature
-            if hasattr(data, 'release'):
-                result['variant_release'] = data.release
-                result['variant_version'] = data.version
-            else:
-                result['variant_release'] = data.version
-                result['variant_version'] = data.stream
+            result = {
+                'variant_id': data.get_name(),
+                'variant_release': data.get_version(),
+                'variant_version': data.get_stream()
+            }
 
         elif is_variant_dict(data):
             result = data.copy()
@@ -308,11 +307,17 @@ class PDCResolver(GenericResolver):
         # module was built. But we still should fallback to plain mmd.requires
         # in case this module depends on some older module for which we did
         # not populate mmd.xmd['mbs']['requires'].
-        if mmd.xmd.get('mbs') and mmd.xmd['mbs'].get('requires'):
-            requires = mmd.xmd['mbs']['requires']
-            requires = {name: data['stream'] for name, data in requires.items()}
+        mbs_xmd = mmd.get_xmd().get('mbs')
+        if 'requires' in mbs_xmd.keys():
+            requires = {name: data['stream'] for name, data in mbs_xmd['requires'].items()}
         else:
-            requires = mmd.requires
+            # Since MBS doesn't support v2 modulemds submitted by a user, we will
+            # always only have one stream per require. That way it's safe to just take the first
+            # element of the list.
+            # TODO: Change this once module stream expansion is implemented
+            requires = {
+                name: deps.get()[0]
+                for name, deps in mmd.get_dependencies()[0].get_requires().items()}
 
         for name, stream in requires.items():
             modified_dep = {
@@ -344,7 +349,7 @@ class PDCResolver(GenericResolver):
         results = {}
         for key in keys:
             results[key] = set()
-        for module_name, module_info in mmd.xmd['mbs']['buildrequires'].items():
+        for module_name, module_info in mmd.get_xmd()['mbs']['buildrequires'].items():
             local_modules = models.ModuleBuild.local_modules(
                 db.session, module_name, module_info['stream'])
             if local_modules:
@@ -353,8 +358,8 @@ class PDCResolver(GenericResolver):
                          local_module)
                 dep_mmd = local_module.mmd()
                 for key in keys:
-                    if key in dep_mmd.profiles:
-                        results[key] |= dep_mmd.profiles[key].rpms
+                    if key in dep_mmd.get_profiles().keys():
+                        results[key] |= set(dep_mmd.get_profiles()[key].get_rpms().get())
                 continue
 
             # Find the dep in the built modules in PDC
@@ -368,11 +373,10 @@ class PDCResolver(GenericResolver):
             for module in modules:
                 yaml = module['modulemd']
                 dep_mmd = self.extract_modulemd(yaml)
-
                 # Take note of what rpms are in this dep's profile.
                 for key in keys:
-                    if key in dep_mmd.profiles:
-                        results[key] |= dep_mmd.profiles[key].rpms
+                    if key in dep_mmd.get_profiles().keys():
+                        results[key] |= set(dep_mmd.get_profiles()[key].get_rpms().get())
 
         # Return the union of all rpms in all profiles of the given keys.
         return results
@@ -398,20 +402,20 @@ class PDCResolver(GenericResolver):
         # This is the set we're going to build up and return.
         module_tags = {}
 
-        if not isinstance(module_info, modulemd.ModuleMetadata):
+        if not isinstance(module_info, Modulemd.Module):
             queried_module = self._get_module(module_info, strict=strict)
             yaml = queried_module['modulemd']
             queried_mmd = self.extract_modulemd(yaml, strict=strict)
         else:
             queried_mmd = module_info
 
-        if (not queried_mmd or 'mbs' not in queried_mmd.xmd or
-                'buildrequires' not in queried_mmd.xmd['mbs']):
+        if (not queried_mmd or not queried_mmd.get_xmd().get('mbs') or
+                'buildrequires' not in queried_mmd.get_xmd()['mbs'].keys()):
             raise RuntimeError(
                 'The module "{0!r}" did not contain its modulemd or did not have '
                 'its xmd attribute filled out in PDC'.format(module_info))
 
-        buildrequires = queried_mmd.xmd['mbs']['buildrequires']
+        buildrequires = queried_mmd.get_xmd()['mbs']['buildrequires']
         # Queue up the next tier of deps that we should look at..
         for name, details in buildrequires.items():
             modified_dep = {
@@ -482,17 +486,16 @@ class PDCResolver(GenericResolver):
             filtered_rpms = []
             module = self._get_module(module_info, strict=True)
             if module.get('modulemd'):
-                mmd = modulemd.ModuleMetadata()
-                mmd.loads(module['modulemd'])
-                if mmd.xmd.get('mbs') and mmd.xmd['mbs'].get('commit'):
-                    commit_hash = mmd.xmd['mbs']['commit']
+                mmd = self.extract_modulemd(module['modulemd'])
+                if mmd.get_xmd().get('mbs') and 'commit' in mmd.get_xmd()['mbs'].keys():
+                    commit_hash = mmd.get_xmd()['mbs']['commit']
 
                 # Find out the particular NVR of filtered packages
-                if "rpms" in module and mmd.filter and mmd.filter.rpms:
+                if "rpms" in module and mmd.get_rpm_filter().get():
                     for rpm in module["rpms"]:
                         nvr = kobo.rpmlib.parse_nvra(rpm)
                         # If the package is not filtered, continue
-                        if not nvr["name"] in mmd.filter.rpms:
+                        if not nvr["name"] in mmd.get_rpm_filter().get():
                             continue
 
                         # If the nvr is already in filtered_rpms, continue
diff --git a/module_build_service/resolver/base.py b/module_build_service/resolver/base.py
index aa51fcfd..0fdc7678 100644
--- a/module_build_service/resolver/base.py
+++ b/module_build_service/resolver/base.py
@@ -26,8 +26,10 @@
 
 import six
 from abc import ABCMeta, abstractmethod
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 
-import modulemd
 import module_build_service.config as cfg
 from module_build_service import conf
 
@@ -88,8 +90,11 @@ class GenericResolver(six.with_metaclass(ABCMeta)):
 
     @staticmethod
     def extract_modulemd(yaml, strict=False):
-        mmd = modulemd.ModuleMetadata()
-        mmd.loads(yaml)
+        try:
+            mmd = Modulemd.Module().new_from_string(yaml)
+            mmd.upgrade()
+        except Exception:
+            raise ValueError('Invalid modulemd')
         return mmd
 
     @abstractmethod
diff --git a/module_build_service/scheduler/handlers/modules.py b/module_build_service/scheduler/handlers/modules.py
index 1714d162..d89079b1 100644
--- a/module_build_service/scheduler/handlers/modules.py
+++ b/module_build_service/scheduler/handlers/modules.py
@@ -146,7 +146,7 @@ def init(config, session, msg):
         mmd = build.mmd()
         record_component_builds(mmd, build, session=session)
         build.build_context, build.runtime_context = build.contexts_from_mmd(mmd.dumps())
-        mmd.context = build.context
+        mmd.set_context(build.context)
         build.modulemd = mmd.dumps()
         build.transition(conf, models.BUILD_STATES["wait"])
     # Catch custom exceptions that we can expose to the user
@@ -181,7 +181,7 @@ def wait(config, session, msg):
     @module_build_service.utils.retry(interval=10, timeout=120, wait_on=RuntimeError)
     def _get_build_containing_xmd_for_mbs():
         build = models.ModuleBuild.from_module_event(session, msg)
-        if 'mbs' in build.mmd().xmd:
+        if 'mbs' in build.mmd().get_xmd():
             return build
         session.expire(build)
         raise RuntimeError("{!r} doesn't contain xmd information for MBS."
@@ -244,7 +244,7 @@ def wait(config, session, msg):
 
             # Find out the name of Koji tag to which the module's Content
             # Generator build should be tagged once the build finishes.
-            module_names_streams = {mmd.name: mmd.stream
+            module_names_streams = {mmd.get_name(): mmd.get_stream()
                                     for mmd in deps_dict.values()}
             for base_module_name in conf.base_module_names:
                 if base_module_name in module_names_streams:
diff --git a/module_build_service/utils.py b/module_build_service/utils.py
index 1a8abfd4..e03e719c 100644
--- a/module_build_service/utils.py
+++ b/module_build_service/utils.py
@@ -33,12 +33,13 @@ import kobo.rpmlib
 import inspect
 import hashlib
 from functools import wraps
-import modulemd
-import yaml
 
 from flask import request, url_for, Response
 from datetime import datetime
 from sqlalchemy.sql.sqltypes import Boolean as sqlalchemy_boolean
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 
 from module_build_service import log, models
 from module_build_service.errors import (ValidationError, UnprocessableEntity,
@@ -48,6 +49,7 @@ from module_build_service.errors import (Forbidden, Conflict)
 import module_build_service.messaging
 from multiprocessing.dummy import Pool as ThreadPool
 import module_build_service.resolver
+from module_build_service import glib
 
 import concurrent.futures
 
@@ -558,7 +560,6 @@ def _fetch_mmd(url, branch=None, allow_local_url=False, whitelist_url=False):
     # and fails to import them because of dep-chain.
     import module_build_service.scm
 
-    yaml = ""
     td = None
     scm = None
     try:
@@ -571,9 +572,7 @@ def _fetch_mmd(url, branch=None, allow_local_url=False, whitelist_url=False):
         scm.checkout(td)
         scm.verify()
         cofn = scm.get_module_yaml()
-
-        with open(cofn, "r") as mmdfile:
-            yaml = mmdfile.read()
+        mmd = load_mmd(cofn, is_file=True)
     finally:
         try:
             if td is not None:
@@ -583,45 +582,65 @@ def _fetch_mmd(url, branch=None, allow_local_url=False, whitelist_url=False):
                 "Failed to remove temporary directory {!r}: {}".format(
                     td, str(e)))
 
-    mmd = load_mmd(yaml)
-
     # If the name was set in the modulemd, make sure it matches what the scmurl
     # says it should be
-    if mmd.name and mmd.name != scm.name:
+    if mmd.get_name() and mmd.get_name() != scm.name:
         raise ValidationError('The name "{0}" that is stored in the modulemd '
-                              'is not valid'.format(mmd.name))
+                              'is not valid'.format(mmd.get_name()))
     else:
-        mmd.name = scm.name
+        mmd.set_name(scm.name)
 
     # If the stream was set in the modulemd, make sure it matches what the repo
     # branch is
-    if mmd.stream and mmd.stream != scm.branch:
+    if mmd.get_stream() and mmd.get_stream() != scm.branch:
         raise ValidationError('The stream "{0}" that is stored in the modulemd '
                               'does not match the branch "{1}"'.format(
-                                  mmd.stream, scm.branch))
+                                  mmd.get_stream(), scm.branch))
     else:
-        mmd.stream = str(scm.branch)
+        mmd.set_stream(str(scm.branch))
 
     # If the version is in the modulemd, throw an exception since the version
     # is generated by pdc-updater
-    if mmd.version:
+    if mmd.get_version():
         raise ValidationError('The version "{0}" is already defined in the '
                               'modulemd but it shouldn\'t be since the version '
                               'is generated based on the commit time'.format(
-                                  mmd.version))
+                                  mmd.get_version()))
     else:
-        mmd.version = int(scm.version)
+        mmd.set_version(int(scm.version))
 
     return mmd, scm
 
 
-def load_mmd(yaml):
-    mmd = modulemd.ModuleMetadata()
+def load_mmd(yaml, is_file=False):
     try:
-        mmd.loads(yaml)
-    except Exception as e:
-        log.error('Invalid modulemd: %s' % str(e))
-        raise UnprocessableEntity('Invalid modulemd: %s' % str(e))
+        if is_file:
+            mmd = Modulemd.Module().new_from_file(yaml)
+        else:
+            mmd = Modulemd.Module().new_from_string(yaml)
+        # If the modulemd was v1, it will be upgraded to v2
+        mmd.upgrade()
+    except Exception:
+        error = 'The following invalid modulemd was encountered: {0}'.format(yaml)
+        log.error(error)
+        raise UnprocessableEntity(error)
+
+    # MBS doesn't support module stream expansion yet but supports the v2 modulemd format,
+    # so if module stream expansion syntax is used, fail the submission
+    # TODO: Once module stream expansion is supported, the get_dependencies() function should
+    # be squashed to a single list on resulting modulemds
+    error_msg = 'Module stream expansion is not yet supported in MBS'
+    deps_list = mmd.get_dependencies()
+    if len(deps_list) > 1:
+        raise UnprocessableEntity(error_msg)
+    elif len(deps_list) == 1:
+        for dep_type in ['requires', 'buildrequires']:
+            deps = getattr(deps_list[0], 'get_{0}'.format(dep_type))()
+            for streams in deps.values():
+                if len(streams.get()) != 1:
+                    raise UnprocessableEntity(error_msg)
+                elif streams.get()[0].startswith('-'):
+                    raise UnprocessableEntity(error)
     return mmd
 
 
@@ -632,15 +651,14 @@ def _scm_get_latest(pkg):
         # to the specific commit available at the time of
         # submission (now).
         pkgref = module_build_service.scm.SCM(
-            pkg.repository).get_latest(pkg.ref)
+            pkg.get_repository()).get_latest(pkg.get_ref())
     except Exception as e:
         log.exception(e)
-        return {
-            'error': "Failed to get the latest commit for %s#%s" % (pkg.repository, pkg.ref)
-        }
+        return {'error': "Failed to get the latest commit for %s#%s" % (
+            pkg.get_repository(), pkg.get_ref())}
 
     return {
-        'pkg_name': pkg.name,
+        'pkg_name': pkg.get_name(),
         'pkg_ref': pkgref,
         'error': None
     }
@@ -711,19 +729,15 @@ def load_local_builds(local_build_nsvs, session=None):
 
         # Load the modulemd metadata.
         path = os.path.join(conf.mock_resultsdir, found_build[3], 'results')
-        mmd_path = os.path.join(path, 'modules.yaml')
-        with open(mmd_path, 'r') as f:
-            mmd_data = yaml.safe_load(f)
-        mmd = modulemd.ModuleMetadata()
-        mmd.loadd(mmd_data)
+        mmd = load_mmd(os.path.join(path, 'modules.yaml'), is_file=True)
 
         # Create ModuleBuild in database.
         module = models.ModuleBuild.create(
             session,
             conf,
-            name=mmd.name,
-            stream=mmd.stream,
-            version=str(mmd.version),
+            name=mmd.get_name(),
+            stream=mmd.get_stream(),
+            version=str(mmd.get_version()),
             modulemd=mmd.dumps(),
             scmurl="",
             username="mbs",
@@ -755,7 +769,8 @@ def format_mmd(mmd, scmurl, session=None):
     if not session:
         session = db.session
 
-    mmd.xmd['mbs'] = {'scmurl': scmurl, 'commit': None}
+    xmd = glib.from_variant_dict(mmd.get_xmd())
+    xmd['mbs'] = {'scmurl': scmurl or '', 'commit': ''}
 
     local_modules = models.ModuleBuild.local_modules(session)
     local_modules = {m.name + "-" + m.stream: m for m in local_modules}
@@ -771,62 +786,56 @@ def format_mmd(mmd, scmurl, session=None):
             else:
                 full_scm_hash = scm.get_full_commit_hash()
 
-            mmd.xmd['mbs']['commit'] = full_scm_hash
+            xmd['mbs']['commit'] = full_scm_hash
         # If a commit hash wasn't provided then just get the latest from master
         else:
-            mmd.xmd['mbs']['commit'] = scm.get_latest()
+            xmd['mbs']['commit'] = scm.get_latest()
 
     resolver = module_build_service.resolver.GenericResolver.create(conf)
 
-    # Resolve Build-requires.
-    if mmd.buildrequires:
-        mmd.xmd['mbs']['buildrequires'] = resolver.resolve_requires(
-            mmd.buildrequires)
-    else:
-        mmd.xmd['mbs']['buildrequires'] = {}
+    # Resolve buildrequires and requires
+    # Reformat the input for resolve_requires to match the old modulemd format
+    dep_obj = mmd.get_dependencies()[0]
+    br_dict = {br: br_list.get()[0] for br, br_list in dep_obj.get_buildrequires().items()}
+    req_dict = {req: req_list.get()[0] for req, req_list in dep_obj.get_requires().items()}
+    xmd['mbs']['buildrequires'] = resolver.resolve_requires(br_dict)
+    xmd['mbs']['requires'] = resolver.resolve_requires(req_dict)
 
-    # Resolve Requires.
-    if mmd.requires:
-        mmd.xmd['mbs']['requires'] = resolver.resolve_requires(mmd.requires)
-    else:
-        mmd.xmd['mbs']['requires'] = {}
-
-    if mmd.components:
-        if 'rpms' not in mmd.xmd['mbs']:
-            mmd.xmd['mbs']['rpms'] = {}
+    if mmd.get_rpm_components() or mmd.get_module_components():
+        if 'rpms' not in xmd['mbs']:
+            xmd['mbs']['rpms'] = {}
         # Add missing data in RPM components
-        for pkgname, pkg in mmd.components.rpms.items():
-            if pkg.repository and not conf.rpms_allow_repository:
+        for pkgname, pkg in mmd.get_rpm_components().items():
+            if pkg.get_repository() and not conf.rpms_allow_repository:
                 raise Forbidden(
                     "Custom component repositories aren't allowed.  "
-                    "%r bears repository %r" % (pkgname, pkg.repository))
-            if pkg.cache and not conf.rpms_allow_cache:
+                    "%r bears repository %r" % (pkgname, pkg.get_repository()))
+            if pkg.get_cache() and not conf.rpms_allow_cache:
                 raise Forbidden(
                     "Custom component caches aren't allowed.  "
                     "%r bears cache %r" % (pkgname, pkg.cache))
-            if not pkg.repository:
-                pkg.repository = conf.rpms_default_repository + pkgname
-            if not pkg.cache:
-                pkg.cache = conf.rpms_default_cache + pkgname
-            if not pkg.ref:
-                pkg.ref = 'master'
+            if not pkg.get_repository():
+                pkg.set_repository(conf.rpms_default_repository + pkgname)
+            if not pkg.get_cache():
+                pkg.set_cache(conf.rpms_default_cache + pkgname)
+            if not pkg.get_ref():
+                pkg.set_ref('master')
 
         # Add missing data in included modules components
-        for modname, mod in mmd.components.modules.items():
-            if mod.repository and not conf.modules_allow_repository:
+        for modname, mod in mmd.get_module_components().items():
+            if mod.get_repository() and not conf.modules_allow_repository:
                 raise Forbidden(
                     "Custom module repositories aren't allowed.  "
-                    "%r bears repository %r" % (modname, mod.repository))
-            if not mod.repository:
-                mod.repository = conf.modules_default_repository + modname
-            if not mod.ref:
-                mod.ref = 'master'
+                    "%r bears repository %r" % (modname, mod.get_repository()))
+            if not mod.get_repository():
+                mod.set_repository(conf.modules_default_repository + modname)
+            if not mod.get_ref():
+                mod.set_ref('master')
 
-        # Check that SCM URL is valid and replace potential branches in
-        # pkg.ref by real SCM hash and store the result to our private xmd
-        # place in modulemd.
+        # Check that SCM URL is valid and replace potential branches in pkg refs
+        # by real SCM hash and store the result to our private xmd place in modulemd.
         pool = ThreadPool(20)
-        pkg_dicts = pool.map(_scm_get_latest, mmd.components.rpms.values())
+        pkg_dicts = pool.map(_scm_get_latest, mmd.get_rpm_components().values())
         err_msg = ""
         for pkg_dict in pkg_dicts:
             if pkg_dict["error"]:
@@ -834,17 +843,20 @@ def format_mmd(mmd, scmurl, session=None):
             else:
                 pkg_name = pkg_dict["pkg_name"]
                 pkg_ref = pkg_dict["pkg_ref"]
-                mmd.xmd['mbs']['rpms'][pkg_name] = {'ref': pkg_ref}
+                xmd['mbs']['rpms'][pkg_name] = {'ref': pkg_ref}
         if err_msg:
             raise UnprocessableEntity(err_msg)
 
+    # Set the modified xmd back to the modulemd
+    mmd.set_xmd(glib.dict_values(xmd))
+
 
 def validate_mmd(mmd):
-    for modname, mod in mmd.components.modules.items():
-        if mod.repository and not conf.modules_allow_repository:
+    for modname, mod in mmd.get_module_components().items():
+        if mod.get_repository() and not conf.modules_allow_repository:
             raise Forbidden(
                 "Custom module repositories aren't allowed.  "
-                "%r bears repository %r" % (modname, mod.repository))
+                "%r bears repository %r" % (modname, mod.get_repository()))
 
 
 def merge_included_mmd(mmd, included_mmd):
@@ -852,11 +864,15 @@ def merge_included_mmd(mmd, included_mmd):
     Merges two modulemds. This merges only metadata which are needed in
     the `main` when it includes another module defined by `included_mmd`
     """
-    if 'rpms' in included_mmd.xmd['mbs']:
-        if 'rpms' not in mmd.xmd['mbs']:
-            mmd.xmd['mbs']['rpms'] = included_mmd.xmd['mbs']['rpms']
+    included_xmd = glib.from_variant_dict(included_mmd.get_xmd())
+    if 'rpms' in included_xmd['mbs']:
+        xmd = glib.from_variant_dict(mmd.get_xmd())
+        if 'rpms' not in xmd['mbs']:
+            xmd['mbs']['rpms'] = included_xmd['mbs']['rpms']
         else:
-            mmd.xmd['mbs']['rpms'].update(included_mmd.xmd['mbs']['rpms'])
+            xmd['mbs']['rpms'].update(included_xmd['mbs']['rpms'])
+    # Set the modified xmd back to the modulemd
+    mmd.set_xmd(glib.dict_values(xmd))
 
 
 def record_component_builds(mmd, module, initial_batch=1,
@@ -876,65 +892,66 @@ def record_component_builds(mmd, module, initial_batch=1,
     if main_mmd:
         # Check for components that are in both MMDs before merging since MBS
         # currently can't handle that situation.
-        duplicate_components = [rpm for rpm in main_mmd.components.rpms.keys()
-                                if rpm in mmd.components.rpms.keys()]
+        duplicate_components = [rpm for rpm in main_mmd.get_rpm_components().keys()
+                                if rpm in mmd.get_rpm_components()]
         if duplicate_components:
             error_msg = (
                 'The included module "{0}" in "{1}" have the following '
-                'conflicting components: {2}'
-                .format(mmd.name, main_mmd.name,
-                        ', '.join(duplicate_components)))
+                'conflicting components: {2}'.format(
+                    mmd.get_name(), main_mmd.get_name(), ', '.join(duplicate_components)))
             raise UnprocessableEntity(error_msg)
         merge_included_mmd(main_mmd, mmd)
     else:
         main_mmd = mmd
 
     # If the modulemd yaml specifies components, then submit them for build
-    if mmd.components:
-        components = mmd.components.all
-        components.sort(key=lambda x: x.buildorder)
+    rpm_components = mmd.get_rpm_components().values()
+    module_components = mmd.get_module_components().values()
+    all_components = rpm_components + module_components
+    if not all_components:
+        return
 
-        weights = module_build_service.builder.GenericBuilder.get_build_weights(
-            [c.name for c in components])
+    rpm_weights = module_build_service.builder.GenericBuilder.get_build_weights(
+        [c.get_name() for c in rpm_components])
+    all_components.sort(key=lambda x: x.get_buildorder())
+    # We do not start with batch = 0 here, because the first batch is
+    # reserved for module-build-macros. First real components must be
+    # planned for batch 2 and following.
+    batch = initial_batch
 
-        # We do not start with batch = 0 here, because the first batch is
-        # reserved for module-build-macros. First real components must be
-        # planned for batch 2 and following.
-        batch = initial_batch
+    for component in all_components:
+        # Increment the batch number when buildorder increases.
+        if previous_buildorder != component.get_buildorder():
+            previous_buildorder = component.get_buildorder()
+            batch += 1
 
-        for pkg in components:
-            # Increment the batch number when buildorder increases.
-            if previous_buildorder != pkg.buildorder:
-                previous_buildorder = pkg.buildorder
-                batch += 1
+        # If the component is another module, we fetch its modulemd file
+        # and record its components recursively with the initial_batch
+        # set to our current batch, so the components of this module
+        # are built in the right global order.
+        if isinstance(component, Modulemd.ComponentModule):
+            full_url = component.get_repository() + "?#" + component.get_ref()
+            # It is OK to whitelist all URLs here, because the validity
+            # of every URL have been already checked in format_mmd(...).
+            included_mmd = _fetch_mmd(full_url, whitelist_url=True)[0]
+            batch = record_component_builds(included_mmd, module, batch,
+                                            previous_buildorder, main_mmd, session=session)
+            continue
 
-            # If the pkg is another module, we fetch its modulemd file
-            # and record its components recursively with the initial_batch
-            # set to our current batch, so the components of this module
-            # are built in the right global order.
-            if isinstance(pkg, modulemd.ModuleComponentModule):
-                full_url = pkg.repository + "?#" + pkg.ref
-                # It is OK to whitelist all URLs here, because the validity
-                # of every URL have been already checked in format_mmd(...).
-                included_mmd = _fetch_mmd(full_url, whitelist_url=True)[0]
-                batch = record_component_builds(included_mmd, module, batch,
-                                                previous_buildorder, main_mmd, session=session)
-                continue
+        component_ref = mmd.get_xmd()['mbs']['rpms'][component.get_name()]['ref']
+        full_url = component.get_repository() + "?#" + component_ref
+        build = models.ComponentBuild(
+            module_id=module.id,
+            package=component.get_name(),
+            format="rpms",
+            scmurl=full_url,
+            batch=batch,
+            ref=component_ref,
+            weight=rpm_weights[component.get_name()]
+        )
+        session.add(build)
 
-            pkgref = mmd.xmd['mbs']['rpms'][pkg.name]['ref']
-            full_url = pkg.repository + "?#" + pkgref
-            build = models.ComponentBuild(
-                module_id=module.id,
-                package=pkg.name,
-                format="rpms",
-                scmurl=full_url,
-                batch=batch,
-                ref=pkgref,
-                weight=weights[pkg.name]
-            )
-            session.add(build)
-
-        return batch
+    return batch
 
 
 def submit_module_build_from_yaml(username, handle, stream=None, skiptests=False,
@@ -949,11 +966,13 @@ def submit_module_build_from_yaml(username, handle, stream=None, skiptests=False
     dt = datetime.utcfromtimestamp(int(time.time()))
     def_name = str(os.path.splitext(os.path.basename(handle.filename))[0])
     def_version = int(dt.strftime("%Y%m%d%H%M%S"))
-    mmd.name = mmd.name or def_name
-    mmd.stream = stream or mmd.stream or "master"
-    mmd.version = mmd.version or def_version
+    mmd.set_name(mmd.get_name() or def_name)
+    mmd.set_stream(stream or mmd.get_stream() or "master")
+    mmd.set_version(mmd.get_version() or def_version)
     if skiptests:
-        mmd.buildopts.rpms.macros += "\n\n%__spec_check_pre exit 0\n"
+        buildopts = mmd.get_rpm_buildopts()
+        buildopts["macros"] = buildopts.get("macros", "") + "\n\n%__spec_check_pre exit 0\n"
+        mmd.set_rpm_buildopts(buildopts)
     return submit_module_build(username, None, mmd, None, optional_params)
 
 
@@ -980,7 +999,7 @@ def submit_module_build(username, url, mmd, scm, optional_params=None):
     # and fails to import them because of dep-chain.
     validate_mmd(mmd)
     module = models.ModuleBuild.query.filter_by(
-        name=mmd.name, stream=mmd.stream, version=str(mmd.version)).first()
+        name=mmd.get_name(), stream=mmd.get_stream(), version=str(mmd.get_version())).first()
     if module:
         log.debug('Checking whether module build already exist.')
         if module.state != models.BUILD_STATES['failed']:
@@ -1015,9 +1034,9 @@ def submit_module_build(username, url, mmd, scm, optional_params=None):
         module = models.ModuleBuild.create(
             db.session,
             conf,
-            name=mmd.name,
-            stream=mmd.stream,
-            version=str(mmd.version),
+            name=mmd.get_name(),
+            stream=mmd.get_stream(),
+            version=str(mmd.get_version()),
             modulemd=mmd.dumps(),
             scmurl=url,
             username=username,
@@ -1027,7 +1046,7 @@ def submit_module_build(username, url, mmd, scm, optional_params=None):
     db.session.add(module)
     db.session.commit()
     log.info("%s submitted build of %s, stream=%s, version=%s", username,
-             mmd.name, mmd.stream, mmd.version)
+             mmd.get_name(), mmd.get_stream(), mmd.get_version())
     return module
 
 
@@ -1141,8 +1160,8 @@ def _get_reusable_module(session, module):
 
     # Find the latest module that is in the done or ready state
     previous_module_build = session.query(models.ModuleBuild)\
-        .filter_by(name=mmd.name)\
-        .filter_by(stream=mmd.stream)\
+        .filter_by(name=mmd.get_name())\
+        .filter_by(stream=mmd.get_stream())\
         .filter(models.ModuleBuild.state.in_([3, 5]))\
         .filter(models.ModuleBuild.scmurl.isnot(None))\
         .order_by(models.ModuleBuild.time_completed.desc())
@@ -1268,10 +1287,10 @@ def get_reusable_component(session, module, component_name,
         is called to get the ModuleBuild instance. Consider passing the ModuleBuild
         instance in case you plan to call get_reusable_component repeatedly for the
         same module to make this method faster.
-    :param mmd: ModuleMetadata of `module`. If not passed, it is taken from
+    :param mmd: ModuleMd.Module of `module`. If not passed, it is taken from
         module.mmd(). Consider passing this arg in case you plan to call
         get_reusable_component repeatedly for the same module to make this method faster.
-    :param old_mmd: ModuleMetadata of `previous_module_build`. If not passed,
+    :param old_mmd: ModuleMd.Module of `previous_module_build`. If not passed,
         it is taken from previous_module_build.mmd(). Consider passing this arg in
         case you plan to call get_reusable_component repeatedly for the same
         module to make this method faster.
@@ -1334,13 +1353,7 @@ def get_reusable_component(session, module, component_name,
             return None
 
         # If the mmd.buildopts.macros.rpms changed, we cannot reuse
-        modulemd_macros = ""
-        old_modulemd_macros = ""
-        if mmd.buildopts and mmd.buildopts.rpms:
-            modulemd_macros = mmd.buildopts.rpms.macros
-        if old_mmd.buildopts and old_mmd.buildopts.rpms:
-            modulemd_macros = old_mmd.buildopts.rpms.macros
-        if modulemd_macros != old_modulemd_macros:
+        if mmd.get_rpm_buildopts().get('macros') != old_mmd.get_rpm_buildopts().get('macros'):
             log.info('Cannot re-use.  Old modulemd macros do not match the new.')
             return None
 
diff --git a/requirements.txt b/requirements.txt
index f6be4715..5e3a15f1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,13 +14,13 @@ koji
 ldap3
 m2crypto
 m2ext
-modulemd>=1.3.3,<2.0.0
 moksha.hub
 munch
 pdc-client
 psutil
 pyOpenSSL
 python-fedora
+pygobject
 requests
 requests_kerberos # Client only
 six
diff --git a/tests/__init__.py b/tests/__init__.py
index 8f6946b1..fadcbc7f 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -26,13 +26,16 @@ from mock import patch
 import time
 from traceback import extract_stack
 
-import modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 import koji
 import module_build_service
 from module_build_service import db
 from module_build_service.utils import get_rpm_release
 from module_build_service.config import init_config
 from module_build_service.models import ModuleBuild, ComponentBuild, make_session, BUILD_STATES
+from module_build_service import glib
 
 
 base_dir = os.path.dirname(__file__)
@@ -271,9 +274,9 @@ def scheduler_init_data(tangerine_state=None):
     current_dir = os.path.dirname(__file__)
     formatted_testmodule_yml_path = os.path.join(
         current_dir, 'staged_data', 'formatted_testmodule.yaml')
-    mmd = modulemd.ModuleMetadata()
-    mmd.load(formatted_testmodule_yml_path)
-    mmd.components.rpms['tangerine'].buildorder = 0
+    mmd = Modulemd.Module().new_from_file(formatted_testmodule_yml_path)
+    mmd.upgrade()
+    mmd.get_rpm_components()['tangerine'].set_buildorder(0)
 
     build_one = module_build_service.models.ModuleBuild()
     build_one.name = 'testmodule'
@@ -376,8 +379,8 @@ def reuse_component_init_data():
     current_dir = os.path.dirname(__file__)
     formatted_testmodule_yml_path = os.path.join(
         current_dir, 'staged_data', 'formatted_testmodule.yaml')
-    mmd = modulemd.ModuleMetadata()
-    mmd.load(formatted_testmodule_yml_path)
+    mmd = Modulemd.Module().new_from_file(formatted_testmodule_yml_path)
+    mmd.upgrade()
 
     build_one = module_build_service.models.ModuleBuild()
     build_one.name = 'testmodule'
@@ -395,9 +398,11 @@ def reuse_component_init_data():
     build_one.time_completed = datetime(2017, 2, 15, 16, 19, 35)
     build_one.rebuild_strategy = 'changed-and-after'
     build_one_component_release = get_rpm_release(build_one)
-    mmd.version = build_one.version
-    mmd.xmd['mbs']['scmurl'] = build_one.scmurl
-    mmd.xmd['mbs']['commit'] = 'ff1ea79fc952143efeed1851aa0aa006559239ba'
+    mmd.set_version(build_one.version)
+    xmd = glib.from_variant_dict(mmd.get_xmd())
+    xmd['mbs']['scmurl'] = build_one.scmurl
+    xmd['mbs']['commit'] = 'ff1ea79fc952143efeed1851aa0aa006559239ba'
+    mmd.set_xmd(glib.dict_values(xmd))
     build_one.modulemd = mmd.dumps()
 
     component_one_build_one = module_build_service.models.ComponentBuild()
@@ -475,9 +480,11 @@ def reuse_component_init_data():
     build_two.time_modified = datetime(2017, 2, 19, 16, 8, 18)
     build_two.rebuild_strategy = 'changed-and-after'
     build_two_component_release = get_rpm_release(build_two)
-    mmd.version = build_one.version
-    mmd.xmd['mbs']['scmurl'] = build_one.scmurl
-    mmd.xmd['mbs']['commit'] = '55f4a0a2e6cc255c88712a905157ab39315b8fd8'
+    mmd.set_version(build_one.version)
+    xmd = glib.from_variant_dict(mmd.get_xmd())
+    xmd['mbs']['scmurl'] = build_one.scmurl
+    xmd['mbs']['commit'] = '55f4a0a2e6cc255c88712a905157ab39315b8fd8'
+    mmd.set_xmd(glib.dict_values(xmd))
     build_two.modulemd = mmd.dumps()
 
     component_one_build_two = module_build_service.models.ComponentBuild()
@@ -540,25 +547,22 @@ def reuse_shared_userspace_init_data():
     clean_database()
 
     with make_session(conf) as session:
-        mmd = modulemd.ModuleMetadata()
-
         # Create shared-userspace-570, state is COMPLETE, all components
         # are properly built.
         current_dir = os.path.dirname(__file__)
         formatted_testmodule_yml_path = os.path.join(
             current_dir, 'staged_data', 'shared-userspace-570.yaml')
-        with open(formatted_testmodule_yml_path, 'r') as f:
-            yaml = f.read()
-            mmd.loads(yaml)
+        mmd = Modulemd.Module().new_from_file(formatted_testmodule_yml_path)
+        mmd.upgrade()
 
         build_one = module_build_service.models.ModuleBuild()
-        build_one.name = mmd.name
-        build_one.stream = mmd.stream
-        build_one.version = mmd.version
+        build_one.name = mmd.get_name()
+        build_one.stream = mmd.get_stream()
+        build_one.version = mmd.get_version()
         build_one.build_context = 'e046b867a400a06a3571f3c71142d497895fefbe'
         build_one.runtime_context = '50dd3eb5dde600d072e45d4120e1548ce66bc94a'
         build_one.state = BUILD_STATES['ready']
-        build_one.modulemd = yaml
+        build_one.modulemd = mmd.dumps()
         build_one.koji_tag = 'module-testmodule-master-20170109091357'
         build_one.scmurl = ('git://pkgs.stg.fedoraproject.org/modules/testmodule.'
                             'git?#7fea453')
@@ -571,21 +575,21 @@ def reuse_shared_userspace_init_data():
 
         session.add(build_one)
 
-        components = mmd.components.all
-        components.sort(key=lambda x: x.buildorder)
+        components = mmd.get_rpm_components().values()
+        components.sort(key=lambda x: x.get_buildorder())
         previous_buildorder = None
         batch = 1
         for pkg in components:
             # Increment the batch number when buildorder increases.
-            if previous_buildorder != pkg.buildorder:
-                previous_buildorder = pkg.buildorder
+            if previous_buildorder != pkg.get_buildorder():
+                previous_buildorder = pkg.get_buildorder()
                 batch += 1
 
-            pkgref = mmd.xmd['mbs']['rpms'][pkg.name]['ref']
-            full_url = pkg.repository + "?#" + pkgref
+            pkgref = mmd.get_xmd()['mbs']['rpms'][pkg.get_name()]['ref']
+            full_url = pkg.get_repository() + "?#" + pkgref
             build = module_build_service.models.ComponentBuild(
                 module_id=1,
-                package=pkg.name,
+                package=pkg.get_name(),
                 format="rpms",
                 scmurl=full_url,
                 batch=batch,
@@ -599,18 +603,17 @@ def reuse_shared_userspace_init_data():
         # Create shared-userspace-577, state is WAIT, no component built
         formatted_testmodule_yml_path = os.path.join(
             current_dir, 'staged_data', 'shared-userspace-577.yaml')
-        with open(formatted_testmodule_yml_path, 'r') as f:
-            yaml = f.read()
-            mmd.loads(yaml)
+        mmd2 = Modulemd.Module().new_from_file(formatted_testmodule_yml_path)
+        mmd2.upgrade()
 
         build_one = module_build_service.models.ModuleBuild()
-        build_one.name = mmd.name
-        build_one.stream = mmd.stream
-        build_one.version = mmd.version
+        build_one.name = mmd2.get_name()
+        build_one.stream = mmd2.get_stream()
+        build_one.version = mmd2.get_version()
         build_one.build_context = 'e046b867a400a06a3571f3c71142d497895fefbe'
         build_one.runtime_context = '50dd3eb5dde600d072e45d4120e1548ce66bc94a'
         build_one.state = BUILD_STATES['done']
-        build_one.modulemd = yaml
+        build_one.modulemd = mmd2.dumps()
         build_one.koji_tag = 'module-testmodule-master-20170109091357'
         build_one.scmurl = ('git://pkgs.stg.fedoraproject.org/modules/testmodule.'
                             'git?#7fea453')
@@ -623,24 +626,24 @@ def reuse_shared_userspace_init_data():
 
         session.add(build_one)
 
-        components = mmd.components.all
+        components2 = mmd2.get_rpm_components().values()
         # Store components to database in different order than for 570 to
         # reproduce the reusing issue.
-        components.sort(key=lambda x: len(x.name))
-        components.sort(key=lambda x: x.buildorder)
+        components2.sort(key=lambda x: len(x.get_name()))
+        components2.sort(key=lambda x: x.get_buildorder())
         previous_buildorder = None
         batch = 1
-        for pkg in components:
+        for pkg in components2:
             # Increment the batch number when buildorder increases.
-            if previous_buildorder != pkg.buildorder:
-                previous_buildorder = pkg.buildorder
+            if previous_buildorder != pkg.get_buildorder():
+                previous_buildorder = pkg.get_buildorder()
                 batch += 1
 
-            pkgref = mmd.xmd['mbs']['rpms'][pkg.name]['ref']
-            full_url = pkg.repository + "?#" + pkgref
+            pkgref = mmd2.get_xmd()['mbs']['rpms'][pkg.get_name()]['ref']
+            full_url = pkg.get_repository() + "?#" + pkgref
             build = module_build_service.models.ComponentBuild(
                 module_id=2,
-                package=pkg.name,
+                package=pkg.get_name(),
                 format="rpms",
                 scmurl=full_url,
                 batch=batch,
diff --git a/tests/conftest.py b/tests/conftest.py
index 060c7e23..87076af1 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -27,15 +27,25 @@ import six
 import pytest
 import mock
 import pdc_client.test_helpers
-import modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
+
+from module_build_service import glib
 
 
 BASE_DIR = os.path.dirname(__file__)
 STAGED_DATA_DIR = os.path.join(BASE_DIR, 'staged_data')
-with open(os.path.join(STAGED_DATA_DIR, 'platform.yaml')) as f:
-    PLATFORM_MODULEMD = f.read()
-with open(os.path.join(STAGED_DATA_DIR, 'formatted_testmodule.yaml')) as f:
-    TESTMODULE_MODULEMD = f.read()
+
+_mmd = Modulemd.Module().new_from_file(
+    os.path.join(STAGED_DATA_DIR, 'platform.yaml'))
+_mmd.upgrade()
+PLATFORM_MODULEMD = _mmd.dumps()
+
+_mmd2 = Modulemd.Module().new_from_file(
+    os.path.join(STAGED_DATA_DIR, 'formatted_testmodule.yaml'))
+_mmd2.upgrade()
+TESTMODULE_MODULEMD = _mmd2.dumps()
 
 
 class MockPDCFilterAPI(pdc_client.test_helpers.MockAPI):
@@ -172,27 +182,32 @@ def pdc_module_active(pdc_module_inactive):
 def pdc_module_reuse(pdc_module_active):
     # Rename it for clarity
     pdc_module_reuse = pdc_module_active
-    mmd = modulemd.ModuleMetadata()
-    mmd.loads(TESTMODULE_MODULEMD)
-    mmd.version = 20170219191323
-    mmd.xmd['mbs']['scmurl'] = 'git://pkgs.stg.fedoraproject.org/modules/testmodule.git?#ff1ea79'
-    mmd.xmd['mbs']['commit'] = 'ff1ea79fc952143efeed1851aa0aa006559239ba'
+    mmd = Modulemd.Module().new_from_string(TESTMODULE_MODULEMD)
+    mmd.upgrade()
+    mmd.set_version(20170219191323)
+    xmd = glib.from_variant_dict(mmd.get_xmd())
+    xmd['mbs']['scmurl'] = 'git://pkgs.stg.fedoraproject.org/modules/testmodule.git?#ff1ea79'
+    xmd['mbs']['commit'] = 'ff1ea79fc952143efeed1851aa0aa006559239ba'
+    mmd.set_xmd(glib.dict_values(xmd))
     pdc_module_reuse.endpoints['unreleasedvariants']['GET'].append(
         copy.deepcopy(pdc_module_reuse.endpoints['unreleasedvariants']['GET'][-1]))
     pdc_module_reuse.endpoints['unreleasedvariants']['GET'][-1].update({
-        'variant_uid': 'testmodule:master:{0}'.format(mmd.version),
-        'variant_release': str(mmd.version),
+        'variant_uid': 'testmodule:master:{0}'.format(mmd.get_version()),
+        'variant_release': str(mmd.get_version()),
         'modulemd': mmd.dumps(),
         'koji_tag': 'module-de3adf79caf3e1b8'
     })
-    mmd.version = 20180205135154
-    mmd.xmd['mbs']['scmurl'] = 'git://pkgs.stg.fedoraproject.org/modules/testmodule.git?#55f4a0a'
-    mmd.xmd['mbs']['commit'] = '55f4a0a2e6cc255c88712a905157ab39315b8fd8'
+
+    mmd.set_version(20180205135154)
+    xmd = glib.from_variant_dict(mmd.get_xmd())
+    xmd['mbs']['scmurl'] = 'git://pkgs.stg.fedoraproject.org/modules/testmodule.git?#55f4a0a'
+    xmd['mbs']['commit'] = '55f4a0a2e6cc255c88712a905157ab39315b8fd8'
+    mmd.set_xmd(glib.dict_values(xmd))
     pdc_module_reuse.endpoints['unreleasedvariants']['GET'].append(
         copy.deepcopy(pdc_module_reuse.endpoints['unreleasedvariants']['GET'][-1]))
     pdc_module_reuse.endpoints['unreleasedvariants']['GET'][-1].update({
-        'variant_uid': 'testmodule:master:{0}'.format(mmd.version),
-        'variant_release': str(mmd.version),
+        'variant_uid': 'testmodule:master:{0}'.format(mmd.get_version()),
+        'variant_release': str(mmd.get_version()),
         'modulemd': mmd.dumps(),
         'koji_tag': 'module-fe3adf73caf3e1b7',
         'rpms': [],
diff --git a/tests/staged_data/platform.yaml b/tests/staged_data/platform.yaml
index 048889b5..1e46842f 100644
--- a/tests/staged_data/platform.yaml
+++ b/tests/staged_data/platform.yaml
@@ -1,6 +1,10 @@
+document: modulemd
+version: 1
 data:
   description: Fedora 28 traditional base
   name: platform
+  license:
+    module: [MIT]
   profiles:
     buildroot:
       rpms: [bash, bzip2, coreutils, cpio, diffutils, fedora-release, findutils, gawk,
@@ -17,5 +21,3 @@ data:
       buildrequires: {}
       commit: virtual
       requires: {}
-document: modulemd
-version: 1
diff --git a/tests/staged_data/testmodule_mse.yaml b/tests/staged_data/testmodule_mse.yaml
new file mode 100644
index 00000000..f48df1c8
--- /dev/null
+++ b/tests/staged_data/testmodule_mse.yaml
@@ -0,0 +1,39 @@
+document: modulemd
+version: 2
+data:
+  summary: A test module in all its beautiful beauty
+  description: >-
+    This module demonstrates how to write simple modulemd files And can be used for
+    testing the build and release pipeline.
+  license:
+    module:
+    - MIT
+  dependencies:
+  - buildrequires:
+      platform: []
+    requires:
+      platform: []
+      font: [a, b, c]
+  references:
+    community: https://docs.pagure.org/modularity/
+    documentation: https://fedoraproject.org/wiki/Fedora_Packaging_Guidelines_for_Modules
+  profiles:
+    default:
+      rpms:
+      - tangerine
+  api:
+    rpms:
+    - perl-Tangerine
+    - tangerine
+  components:
+    rpms:
+      perl-List-Compare:
+        rationale: A dependency of tangerine.
+        ref: master
+      perl-Tangerine:
+        rationale: Provides API for this module and is a dependency of tangerine.
+        ref: master
+      tangerine:
+        rationale: Provides API for this module.
+        ref: master
+        buildorder: 10
diff --git a/tests/staged_data/testmodule_v2.yaml b/tests/staged_data/testmodule_v2.yaml
new file mode 100644
index 00000000..463e1dcc
--- /dev/null
+++ b/tests/staged_data/testmodule_v2.yaml
@@ -0,0 +1,38 @@
+document: modulemd
+version: 2
+data:
+  summary: A test module in all its beautiful beauty
+  description: >-
+    This module demonstrates how to write simple modulemd files And can be used for
+    testing the build and release pipeline.
+  license:
+    module:
+    - MIT
+  dependencies:
+  - buildrequires:
+      platform: [f28]
+    requires:
+      platform: [f28]
+  references:
+    community: https://docs.pagure.org/modularity/
+    documentation: https://fedoraproject.org/wiki/Fedora_Packaging_Guidelines_for_Modules
+  profiles:
+    default:
+      rpms:
+      - tangerine
+  api:
+    rpms:
+    - perl-Tangerine
+    - tangerine
+  components:
+    rpms:
+      perl-List-Compare:
+        rationale: A dependency of tangerine.
+        ref: master
+      perl-Tangerine:
+        rationale: Provides API for this module and is a dependency of tangerine.
+        ref: master
+      tangerine:
+        rationale: Provides API for this module.
+        ref: master
+        buildorder: 10
diff --git a/tests/test_build/test_build.py b/tests/test_build/test_build.py
index 3edcc24d..c0835aa7 100644
--- a/tests/test_build/test_build.py
+++ b/tests/test_build/test_build.py
@@ -37,6 +37,7 @@ from module_build_service import db, models, conf, build_logs
 from mock import patch, PropertyMock, Mock
 from werkzeug.datastructures import FileStorage
 import kobo
+import pytest
 
 from tests import app, reuse_component_init_data, clean_database
 import json
@@ -317,15 +318,20 @@ class TestBuild:
             except Exception:
                 pass
 
+    @pytest.mark.parametrize('mmd_version', [1, 2])
     @patch('module_build_service.auth.get_user', return_value=user)
     @patch('module_build_service.scm.SCM')
     def test_submit_build(self, mocked_scm, mocked_get_user, conf_system, dbg,
-                          pdc_module_inactive):
+                          pdc_module_inactive, mmd_version):
         """
         Tests the build of testmodule.yaml using FakeModuleBuilder which
         succeeds everytime.
         """
-        FakeSCM(mocked_scm, 'testmodule', 'testmodule.yaml',
+        if mmd_version == 1:
+            yaml_file = 'testmodule.yaml'
+        else:
+            yaml_file = 'testmodule_v2.yaml'
+        FakeSCM(mocked_scm, 'testmodule', yaml_file,
                 '620ec77321b2ea7b0d67d82992dda3e1d67055b4')
 
         rv = self.client.post('/module-build-service/1/module-builds/', data=json.dumps(
diff --git a/tests/test_builder/test_mock.py b/tests/test_builder/test_mock.py
index 4c546915..d211c58a 100644
--- a/tests/test_builder/test_mock.py
+++ b/tests/test_builder/test_mock.py
@@ -5,10 +5,14 @@ import tempfile
 import shutil
 
 import kobo.rpmlib
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 
 from module_build_service import conf
 from module_build_service.models import ModuleBuild, ComponentBuild, make_session
 from module_build_service.builder.MockModuleBuilder import MockModuleBuilder
+from module_build_service import glib
 from tests import clean_database
 
 
@@ -45,56 +49,55 @@ class TestMockModuleBuilder:
         ]
 
         base_dir = os.path.abspath(os.path.dirname(__file__))
-        modulemd_path = os.path.join(
-            base_dir, '..', 'staged_data', 'testmodule-with-filters.yaml')
+        mmd = Modulemd.Module().new_from_file(os.path.join(
+            base_dir, '..', 'staged_data', 'testmodule-with-filters.yaml'))
+        mmd.upgrade()
 
-        with open(modulemd_path, "r") as fd:
-            module = ModuleBuild.create(
-                session,
-                conf,
-                name="mbs-testmodule",
-                stream="test",
-                version="20171027111452",
-                modulemd=fd.read(),
-                scmurl="file:///testdir",
-                username="test",
-            )
-            module.koji_tag = "module-mbs-testmodule-test-20171027111452"
-            md = module.mmd()
-            md.xmd = {
-                'mbs': {
-                    'rpms': {
-                        'ed': {'ref': '01bf8330812fea798671925cc537f2f29b0bd216'},
-                        'mksh': {'ref': 'f70fd11ddf96bce0e2c64309706c29156b39141d'}
+        module = ModuleBuild.create(
+            session,
+            conf,
+            name="mbs-testmodule",
+            stream="test",
+            version="20171027111452",
+            modulemd=mmd.dumps(),
+            scmurl="file:///testdir",
+            username="test",
+        )
+        module.koji_tag = "module-mbs-testmodule-test-20171027111452"
+        mmd.set_xmd(glib.dict_values({
+            'mbs': {
+                'rpms': {
+                    'ed': {'ref': '01bf8330812fea798671925cc537f2f29b0bd216'},
+                    'mksh': {'ref': 'f70fd11ddf96bce0e2c64309706c29156b39141d'}
+                },
+                'buildrequires':
+                {
+                    'host': {
+                        'version': '20171024133034',
+                        'filtered_rpms': [],
+                        'stream': 'master',
+                        'ref': '6df253bb3c53e84706c01b8ab2d5cac24f0b6d45'
                     },
-                    'buildrequires':
-                    {
-                        'host': {
-                            'version': '20171024133034',
-                            'filtered_rpms': [],
-                            'stream': 'master',
-                            'ref': '6df253bb3c53e84706c01b8ab2d5cac24f0b6d45'
-                        },
-                        'platform': {
-                            'version': '20171028112959',
-                            'filtered_rpms': [],
-                            'stream': 'master',
-                            'ref': '4f7787370a931d57421f9f9555fc41c3e31ff1fa'}
-                    },
-                    'scmurl': 'file:///testdir',
-                    'commit': '5566bc792ec7a03bb0e28edd1b104a96ba342bd8',
-                    'requires': {
-                        'platform': {
-                            'version': '20171028112959',
-                            'filtered_rpms': [],
-                            'stream': 'master',
-                            'ref': '4f7787370a931d57421f9f9555fc41c3e31ff1fa'}
-                    }
+                    'platform': {
+                        'version': '20171028112959',
+                        'filtered_rpms': [],
+                        'stream': 'master',
+                        'ref': '4f7787370a931d57421f9f9555fc41c3e31ff1fa'}
+                },
+                'scmurl': 'file:///testdir',
+                'commit': '5566bc792ec7a03bb0e28edd1b104a96ba342bd8',
+                'requires': {
+                    'platform': {
+                        'version': '20171028112959',
+                        'filtered_rpms': [],
+                        'stream': 'master',
+                        'ref': '4f7787370a931d57421f9f9555fc41c3e31ff1fa'}
                 }
             }
-            module.modulemd = md.dumps()
-            module.batch = batch
-            session.add(module)
+        }))
+        module.modulemd = mmd.dumps()
+        module.batch = batch
+        session.add(module)
 
         for build in comp_builds:
             cb = ComponentBuild(**dict(build, format="rpms", state=state))
diff --git a/tests/test_models/__init__.py b/tests/test_models/__init__.py
index 4585689a..8c8b9406 100644
--- a/tests/test_models/__init__.py
+++ b/tests/test_models/__init__.py
@@ -21,11 +21,13 @@
 # Written by Ralph Bean <rbean@redhat.com>
 
 import os
+from datetime import datetime
 
 import module_build_service
-import modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 
-from datetime import datetime
 from tests import db, clean_database
 from module_build_service.config import init_config
 from module_build_service.models import ModuleBuild, BUILD_STATES
@@ -38,13 +40,12 @@ datadir = os.path.dirname(__file__) + '/data/'
 
 
 def module_build_from_modulemd(yaml):
-    mmd = modulemd.ModuleMetadata()
-    mmd.loads(yaml)
-
+    mmd = Modulemd.Module().new_from_string(yaml)
+    mmd.upgrade()
     build = ModuleBuild()
-    build.name = mmd.name
-    build.stream = mmd.stream
-    build.version = mmd.version
+    build.name = mmd.get_name()
+    build.stream = mmd.get_stream()
+    build.version = mmd.get_version()
     build.state = BUILD_STATES['ready']
     build.modulemd = yaml
     build.koji_tag = None
diff --git a/tests/test_models/test_models.py b/tests/test_models/test_models.py
index 88072f8e..c5bd6672 100644
--- a/tests/test_models/test_models.py
+++ b/tests/test_models/test_models.py
@@ -22,7 +22,9 @@
 
 import os
 
-import modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 
 from tests.test_models import init_data
 from module_build_service import conf
@@ -63,10 +65,10 @@ class TestModels:
         """ Test that the build_context, runtime_context, and context hashes are correctly
         determined"""
         build = ModuleBuild.query.filter_by(id=1).one()
-        mmd = modulemd.ModuleMetadata()
         yaml_path = os.path.join(
             os.path.dirname(__file__), '..', 'staged_data', 'testmodule_dependencies.yaml')
-        mmd.load(yaml_path)
+        mmd = Modulemd.Module().new_from_file(yaml_path)
+        mmd.upgrade()
         build.modulemd = mmd.dumps()
         build.build_context, build.runtime_context = ModuleBuild.contexts_from_mmd(build.modulemd)
         assert build.build_context == 'f6e2aeec7576196241b9afa0b6b22acf2b6873d7'
diff --git a/tests/test_resolver/test_pdc.py b/tests/test_resolver/test_pdc.py
index 88aa73f8..7619d0f1 100644
--- a/tests/test_resolver/test_pdc.py
+++ b/tests/test_resolver/test_pdc.py
@@ -25,14 +25,16 @@ import copy
 
 from mock import patch, PropertyMock
 import pytest
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 
 import module_build_service.resolver as mbs_resolver
 import module_build_service.utils
 import module_build_service.models
 from module_build_service import app, db
-
+from module_build_service import glib
 import tests
-import modulemd
 
 
 base_dir = os.path.join(os.path.dirname(__file__), "..")
@@ -76,10 +78,12 @@ class TestPDCModule:
         if empty_buildrequires:
             expected = set()
             pdc_item = pdc_module_active.endpoints['unreleasedvariants']['GET'][-1]
-            mmd = modulemd.ModuleMetadata()
-            mmd.loads(pdc_item['modulemd'])
-            mmd.buildrequires = {}
-            mmd.xmd['mbs']['buildrequires'] = {}
+            mmd = Modulemd.Module().new_from_string(pdc_item['modulemd'])
+            # Wipe out the dependencies
+            mmd.set_dependencies()
+            xmd = glib.from_variant_dict(mmd.get_xmd())
+            xmd['mbs']['buildrequires'] = {}
+            mmd.set_xmd(glib.dict_values(xmd))
             pdc_item.update({
                 'modulemd': mmd.dumps(),
                 'build_deps': []
@@ -101,21 +105,25 @@ class TestPDCModule:
         pdc_module_active.endpoints['unreleasedvariants']['GET'].append(
             copy.deepcopy(pdc_module_active.endpoints['unreleasedvariants']['GET'][-1]))
         pdc_item = pdc_module_active.endpoints['unreleasedvariants']['GET'][-1]
-        mmd = modulemd.ModuleMetadata()
-        mmd.loads(pdc_item['modulemd'])
-        mmd.name = 'testmodule2'
-        mmd.version = 20180123171545
-        mmd.requires['testmodule'] = 'master'
-        mmd.xmd['mbs']['requires']['testmodule'] = {
+        mmd = Modulemd.Module().new_from_string(pdc_item['modulemd'])
+        mmd.set_name('testmodule2')
+        mmd.set_version(20180123171545)
+        requires = mmd.get_dependencies()[0].get_requires()
+        requires['testmodule'] = Modulemd.SimpleSet()
+        requires['testmodule'].add('master')
+        mmd.get_dependencies()[0].set_requires(requires)
+        xmd = glib.from_variant_dict(mmd.get_xmd())
+        xmd['mbs']['requires']['testmodule'] = {
             'filtered_rpms': [],
             'ref': '620ec77321b2ea7b0d67d82992dda3e1d67055b4',
             'stream': 'master',
             'version': '20180205135154'
         }
+        mmd.set_xmd(glib.dict_values(xmd))
         pdc_item.update({
             'variant_id': 'testmodule2',
             'variant_name': 'testmodule2',
-            'variant_release': str(mmd.version),
+            'variant_release': str(mmd.get_version()),
             'koji_tag': 'module-ae2adf69caf0e1b6',
             'modulemd': mmd.dumps()
         })
@@ -164,8 +172,8 @@ class TestPDCModule:
     def test_resolve_profiles(self, pdc_module_active):
         yaml_path = os.path.join(
             base_dir, 'staged_data', 'formatted_testmodule.yaml')
-        mmd = modulemd.ModuleMetadata()
-        mmd.load(yaml_path)
+        mmd = Modulemd.Module().new_from_file(yaml_path)
+        mmd.upgrade()
         resolver = mbs_resolver.GenericResolver.create(tests.conf, backend='pdc')
         result = resolver.resolve_profiles(mmd, ('buildroot', 'srpm-buildroot'))
         expected = {
@@ -193,8 +201,8 @@ class TestPDCModule:
 
             yaml_path = os.path.join(
                 base_dir, 'staged_data', 'formatted_testmodule.yaml')
-            mmd = modulemd.ModuleMetadata()
-            mmd.load(yaml_path)
+            mmd = Modulemd.Module().new_from_file(yaml_path)
+            mmd.upgrade()
             resolver = mbs_resolver.GenericResolver.create(tests.conf, backend='pdc')
             result = resolver.resolve_profiles(mmd, ('buildroot', 'srpm-buildroot'))
             expected = {
diff --git a/tests/test_scheduler/test_module_init.py b/tests/test_scheduler/test_module_init.py
index fe940fe6..c4430dfe 100644
--- a/tests/test_scheduler/test_module_init.py
+++ b/tests/test_scheduler/test_module_init.py
@@ -22,6 +22,7 @@
 import os
 
 from mock import patch, PropertyMock
+from gi.repository import GLib
 
 from tests import conf, clean_database
 from tests.test_views.test_views import FakeSCM
@@ -66,7 +67,7 @@ class TestModuleInit:
         # Make sure the module entered the wait state
         assert build.state == 1, build.state
         # Make sure format_mmd was run properly
-        assert type(build.mmd().xmd['mbs']) is dict
+        assert type(build.mmd().get_xmd()['mbs']) is GLib.Variant
 
     @patch('module_build_service.scm.SCM')
     def test_init_scm_not_available(self, mocked_scm, pdc):
@@ -120,7 +121,7 @@ class TestModuleInit:
             'foo': {'ref': '93dea37599'},
             'file': {'ref': 'a2740663f8'},
         }
-        assert build.mmd().xmd['mbs']['rpms'] == xmd_rpms
+        assert build.mmd().get_xmd()['mbs']['rpms'] == xmd_rpms
 
     @patch('module_build_service.models.ModuleBuild.from_module_event')
     @patch('module_build_service.scm.SCM')
diff --git a/tests/test_scheduler/test_module_wait.py b/tests/test_scheduler/test_module_wait.py
index badd7744..9f121ee7 100644
--- a/tests/test_scheduler/test_module_wait.py
+++ b/tests/test_scheduler/test_module_wait.py
@@ -24,7 +24,9 @@ import mock
 from mock import patch
 import module_build_service.messaging
 import module_build_service.scheduler.handlers.modules
-import modulemd as _modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 import os
 import koji
 from tests import conf, db, app, scheduler_init_data
@@ -66,12 +68,10 @@ class TestModuleWait:
         }
         mocked_module_build.extended_json = mocked_module_build.json
 
-        mmd = _modulemd.ModuleMetadata()
         formatted_testmodule_yml_path = os.path.join(
             base_dir, 'staged_data', 'formatted_testmodule.yaml')
-        with open(formatted_testmodule_yml_path, 'r') as f:
-            mmd.loads(f)
-
+        mmd = Modulemd.Module().new_from_file(formatted_testmodule_yml_path)
+        mmd.upgrade()
         mocked_module_build.id = 1
         mocked_module_build.mmd.return_value = mmd
         mocked_module_build.component_builds = []
@@ -172,9 +172,9 @@ class TestModuleWait:
         Test that build.cg_build_koji_tag fallbacks to default tag.
         """
         with app.app_context():
-            base_mmd = _modulemd.ModuleMetadata()
-            base_mmd.name = "base-runtime"
-            base_mmd.stream = "f27"
+            base_mmd = Modulemd.Module()
+            base_mmd.set_name("base-runtime")
+            base_mmd.set_stream("f27")
 
             scheduler_init_data()
             koji_session = mock.MagicMock()
@@ -217,9 +217,9 @@ class TestModuleWait:
         Test that build.cg_build_koji_tag is set.
         """
         with app.app_context():
-            base_mmd = _modulemd.ModuleMetadata()
-            base_mmd.name = "base-runtime"
-            base_mmd.stream = "f27"
+            base_mmd = Modulemd.Module()
+            base_mmd.set_name("base-runtime")
+            base_mmd.set_stream("f27")
 
             scheduler_init_data()
             koji_session = mock.MagicMock()
diff --git a/tests/test_utils/test_utils.py b/tests/test_utils/test_utils.py
index 627c1192..5ffd9c14 100644
--- a/tests/test_utils/test_utils.py
+++ b/tests/test_utils/test_utils.py
@@ -22,7 +22,9 @@ import tempfile
 from os import path, mkdir
 from shutil import copyfile, rmtree
 from datetime import datetime
-import modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 from werkzeug.datastructures import FileStorage
 from mock import patch
 import module_build_service.utils
@@ -37,6 +39,7 @@ import pytest
 import module_build_service.scheduler.handlers.components
 from module_build_service.builder.base import GenericBuilder
 from module_build_service.builder.KojiModuleBuilder import KojiModuleBuilder
+from module_build_service import glib
 from tests import app
 
 BASE_DIR = path.abspath(path.dirname(__file__))
@@ -90,7 +93,8 @@ class TestUtilsComponentReuse:
         second_module_build = models.ModuleBuild.query.filter_by(id=2).one()
         if changed_component:
             mmd = second_module_build.mmd()
-            mmd.components.rpms[changed_component].ref = '00ea1da4192a2030f9ae023de3b3143ed647bbab'
+            mmd.get_rpm_components()['tangerine'].set_ref(
+                '00ea1da4192a2030f9ae023de3b3143ed647bbab')
             second_module_build.modulemd = mmd.dumps()
             second_module_changed_component = models.ComponentBuild.query.filter_by(
                 package=changed_component, module_id=2).one()
@@ -130,7 +134,7 @@ class TestUtilsComponentReuse:
     def test_get_reusable_component_different_rpm_macros(self):
         second_module_build = models.ModuleBuild.query.filter_by(id=2).one()
         mmd = second_module_build.mmd()
-        mmd.buildopts.rpms.macros = "%my_macro 1"
+        mmd.set_rpm_buildopts({'macros': '%my_macro 1'})
         second_module_build.modulemd = mmd.dumps()
         db.session.commit()
 
@@ -145,8 +149,10 @@ class TestUtilsComponentReuse:
     def test_get_reusable_component_different_buildrequires_hash(self):
         second_module_build = models.ModuleBuild.query.filter_by(id=2).one()
         mmd = second_module_build.mmd()
-        mmd.xmd['mbs']['buildrequires']['platform']['ref'] = \
+        xmd = glib.from_variant_dict(mmd.get_xmd())
+        xmd['mbs']['buildrequires']['platform']['ref'] = \
             'da39a3ee5e6b4b0d3255bfef95601890afd80709'
+        mmd.set_xmd(glib.dict_values(xmd))
         second_module_build.modulemd = mmd.dumps()
         second_module_build.build_context = '37c6c57bedf4305ef41249c1794760b5cb8fad17'
         db.session.commit()
@@ -166,14 +172,18 @@ class TestUtilsComponentReuse:
     def test_get_reusable_component_different_buildrequires(self):
         second_module_build = models.ModuleBuild.query.filter_by(id=2).one()
         mmd = second_module_build.mmd()
-        mmd.buildrequires = {'some_module': 'master'}
-        mmd.xmd['mbs']['buildrequires'] = {
+        br_list = Modulemd.SimpleSet()
+        br_list.add('master')
+        mmd.get_dependencies()[0].set_buildrequires({'some_module': br_list})
+        xmd = glib.from_variant_dict(mmd.get_xmd())
+        xmd['mbs']['buildrequires'] = {
             'some_module': {
                 'ref': 'da39a3ee5e6b4b0d3255bfef95601890afd80709',
                 'stream': 'master',
                 'version': '20170123140147'
             }
         }
+        mmd.set_xmd(glib.dict_values(xmd))
         second_module_build.modulemd = mmd.dumps()
         second_module_build.build_context = '37c6c57bedf4305ef41249c1794760b5cb8fad17'
         db.session.commit()
@@ -218,8 +228,8 @@ class TestUtilsComponentReuse:
             mock_submit_args = mock_submit.call_args[0]
             username_arg = mock_submit_args[0]
             mmd_arg = mock_submit_args[2]
-            assert mmd_arg.stream == stream
-            assert "\n\n%__spec_check_pre exit 0\n" in mmd_arg.buildopts.rpms.macros
+            assert mmd_arg.get_stream() == stream
+            assert "\n\n%__spec_check_pre exit 0\n" in mmd_arg.get_rpm_buildopts()['macros']
             assert username_arg == username
         rmtree(module_dir)
 
@@ -254,21 +264,23 @@ class TestUtils:
             return hashes_returned[ref]
 
         mocked_scm.return_value.get_latest = mocked_get_latest
-        mmd = modulemd.ModuleMetadata()
-        mmd.load(path.join(BASE_DIR, '..', 'staged_data', 'testmodule.yaml'))
+        mmd = Modulemd.Module().new_from_file(
+            path.join(BASE_DIR, '..', 'staged_data', 'testmodule.yaml'))
+        mmd.upgrade()
         # Modify the component branches so we can identify them later on
-        mmd.components.rpms['perl-Tangerine'].ref = 'f28'
-        mmd.components.rpms['tangerine'].ref = 'f27'
+        mmd.get_rpm_components()['perl-Tangerine'].set_ref('f28')
+        mmd.get_rpm_components()['tangerine'].set_ref('f27')
         module_build_service.utils.format_mmd(mmd, scmurl)
 
         # Make sure that original refs are not changed.
-        mmd_pkg_refs = [pkg.ref for pkg in mmd.components.rpms.values()]
+        mmd_pkg_refs = [pkg.get_ref() for pkg in mmd.get_rpm_components().values()]
         assert set(mmd_pkg_refs) == set(hashes_returned.keys())
-
-        assert mmd.buildrequires == {'platform': 'f28'}
+        br = mmd.get_dependencies()[0].get_buildrequires()
+        assert br.keys() == ['platform']
+        assert br.values()[0].get() == ['f28']
         xmd = {
             'mbs': {
-                'commit': None,
+                'commit': '',
                 'buildrequires': {
                     'platform': {
                         'ref': 'virtual',
@@ -285,14 +297,14 @@ class TestUtils:
                     'perl-List-Compare': {'ref': 'fbed359411a1baa08d4a88e0d12d426fbf8f602c'},
                     'perl-Tangerine': {'ref': '4ceea43add2366d8b8c5a622a2fb563b625b9abf'},
                     'tangerine': {'ref': '5deef23acd2367d8b8d5a621a2fc568b695bc3bd'}},
-                'scmurl': None
+                'scmurl': ''
             }
         }
         if scmurl:
             xmd['mbs']['commit'] = '620ec77321b2ea7b0d67d82992dda3e1d67055b4'
             xmd['mbs']['scmurl'] = scmurl
-
-        assert mmd.xmd == xmd
+        mmd_xmd = glib.from_variant_dict(mmd.get_xmd())
+        assert mmd_xmd == xmd
 
     def test_get_reusable_component_shared_userspace_ordering(self):
         """
@@ -423,9 +435,9 @@ class TestUtils:
                 'fbed359411a1baa08d4a88e0d12d426fbf8f602c']
 
             testmodule_mmd_path = path.join(BASE_DIR, '..', 'staged_data', 'testmodule.yaml')
-            mmd = modulemd.ModuleMetadata()
-            mmd.load(testmodule_mmd_path)
-            mmd.name = 'testmodule-variant'
+            mmd = Modulemd.Module().new_from_file(testmodule_mmd_path)
+            mmd.upgrade()
+            mmd.set_name('testmodule-variant')
             module_build = module_build_service.models.ModuleBuild()
             module_build.name = 'testmodule-variant'
             module_build.stream = 'master'
@@ -441,11 +453,13 @@ class TestUtils:
             db.session.add(module_build)
             db.session.commit()
             # Rename the the modulemd to include
-            mmd.name = 'testmodule'
+            mmd.set_name('testmodule')
             # Remove perl-Tangerine and tangerine from the modulemd to include so only one
             # component conflicts
-            mmd.components.rpms.pop('perl-Tangerine')
-            mmd.components.rpms.pop('tangerine')
+            comps = mmd.get_rpm_components()
+            del comps['perl-Tangerine']
+            del comps['tangerine']
+            mmd.set_rpm_components(comps)
 
             error_msg = (
                 'The included module "testmodule" in "testmodule-variant" have '
@@ -469,8 +483,8 @@ class TestUtils:
 
             testmodule_mmd_path = path.join(
                 BASE_DIR, '..', 'staged_data', 'testmodule.yaml')
-            mmd = modulemd.ModuleMetadata()
-            mmd.load(testmodule_mmd_path)
+            mmd = Modulemd.Module().new_from_file(testmodule_mmd_path)
+            mmd.upgrade()
             module_build = module_build_service.models.ModuleBuild()
             module_build.name = 'testmodule'
             module_build.stream = 'master'
diff --git a/tests/test_views/test_views.py b/tests/test_views/test_views.py
index 159a77f2..5e962dd0 100644
--- a/tests/test_views/test_views.py
+++ b/tests/test_views/test_views.py
@@ -22,7 +22,9 @@
 
 import json
 
-import modulemd as _modulemd
+import gi
+gi.require_version('Modulemd', '1.0')  # noqa
+from gi.repository import Modulemd
 import module_build_service.scm
 
 from mock import patch, PropertyMock
@@ -533,8 +535,8 @@ class TestViews:
         assert len(data['state_trace']) == 1
         assert data['state_trace'][0]['state'] == 0
         assert data['tasks'] == {}
-        mmd = _modulemd.ModuleMetadata()
-        mmd.loads(data["modulemd"])
+        mmd = Modulemd.Module().new_from_string(data['modulemd'])
+        mmd.upgrade()
 
     @patch('module_build_service.auth.get_user', return_value=user)
     @patch('module_build_service.scm.SCM')
@@ -661,7 +663,7 @@ class TestViews:
             {'branch': 'master', 'scmurl': 'git://pkgs.stg.fedoraproject.org/modules/'
                 'testmodule.git?#68931c90de214d9d13feefbd35246a81b6cb8d49'}))
         data = json.loads(rv.data)
-        assert data['message'].startswith('Invalid modulemd:') is True
+        assert data['message'].startswith('The following invalid modulemd was encountered') is True
         assert data['status'] == 422
         assert data['error'] == 'Unprocessable Entity'
 
@@ -806,6 +808,20 @@ class TestViews:
                                    'does not match the branch "master"')
         assert data['error'] == 'Bad Request'
 
+    @patch('module_build_service.auth.get_user', return_value=user)
+    @patch('module_build_service.scm.SCM')
+    def test_submit_build_mse_unsupported(self, mocked_scm, mocked_get_user):
+        FakeSCM(mocked_scm, 'testmodule', 'testmodule_mse.yaml',
+                '620ec77321b2ea7b0d67d82992dda3e1d67055b4')
+
+        rv = self.client.post('/module-build-service/1/module-builds/', data=json.dumps(
+            {'branch': 'master', 'scmurl': 'git://pkgs.stg.fedoraproject.org/modules/'
+                'testmodule.git?#68931c90de214d9d13feefbd35246a81b6cb8d49'}))
+        data = json.loads(rv.data)
+        assert data['status'] == 422
+        assert data['message'] == 'Module stream expansion is not yet supported in MBS'
+        assert data['error'] == 'Unprocessable Entity'
+
     @patch('module_build_service.auth.get_user', return_value=user)
     def test_submit_build_set_owner(self, mocked_get_user):
         data = {