diff --git a/module_build_service/scheduler/default_modules.py b/module_build_service/scheduler/default_modules.py
index 0e984eea..71038d87 100644
--- a/module_build_service/scheduler/default_modules.py
+++ b/module_build_service/scheduler/default_modules.py
@@ -355,8 +355,11 @@ def _get_rpms_in_external_repo(repo_url, arches, cache_dir_name):
 
     # Add a separate repo for each architecture
     for arch in arches:
-        repo_name = "repo_{}".format(arch)
-        repo_arch_url = repo_url.replace("$arch", arch)
+        # Convert arch to canon_arch. This handles cases where Koji "i686" arch is mapped to
+        # "i386" when generating RPM repository.
+        canon_arch = koji.canonArch(arch)
+        repo_name = "repo_{}".format(canon_arch)
+        repo_arch_url = repo_url.replace("$arch", canon_arch)
         base.repos.add_new_repo(repo_name, dnf_conf, baseurl=[repo_arch_url])
         # Load one repo at a time instead of running `base.update_cache()` so that we know which
         # repo fails to load if one does
diff --git a/tests/test_scheduler/test_default_modules.py b/tests/test_scheduler/test_default_modules.py
index cae70b94..4462a723 100644
--- a/tests/test_scheduler/test_default_modules.py
+++ b/tests/test_scheduler/test_default_modules.py
@@ -398,10 +398,12 @@ def test_get_rpms_in_external_repo(mock_makedirs, mock_dnf_base):
         RPM("aarch64", 0, "python", "1.el8", "3.7"),
         RPM("x86_64", 0, "python", "1.el8", "2.7"),
         RPM("x86_64", 0, "python", "1.el8", "3.7"),
+        RPM("i686", 0, "python", "1.el8", "2.7"),
+        RPM("i686", 0, "python", "1.el8", "3.7"),
     ]
 
     external_repo_url = "http://domain.local/repo/latest/$arch/"
-    arches = ["aarch64", "x86_64"]
+    arches = ["aarch64", "x86_64", "i686"]
     cache_dir_name = "module-el-build-12"
     rv = default_modules._get_rpms_in_external_repo(external_repo_url, arches, cache_dir_name)
 
@@ -410,9 +412,16 @@ def test_get_rpms_in_external_repo(mock_makedirs, mock_dnf_base):
         "python-0:3.7-1.el8.aarch64",
         "python-0:2.7-1.el8.x86_64",
         "python-0:3.7-1.el8.x86_64",
+        "python-0:2.7-1.el8.i686",
+        "python-0:3.7-1.el8.i686",
     }
     assert rv == expected
 
+    # Test that i686 is mapped to i386 using the koji.canonArch().
+    mock_dnf_base.return_value.repos.add_new_repo.assert_called_with(
+        'repo_i386', mock_dnf_base.return_value.conf,
+        baseurl=['http://domain.local/repo/latest/i386/'])
+
 
 def test_get_rpms_in_external_repo_invalid_repo_url():
     """