diff --git a/backend/src/module/models/config.py b/backend/src/module/models/config.py
index 49044fa3..1ebaa430 100644
--- a/backend/src/module/models/config.py
+++ b/backend/src/module/models/config.py
@@ -1,7 +1,7 @@
 from os.path import expandvars
 from typing import Literal
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, validator
 
 
 class Program(BaseModel):
@@ -102,6 +102,12 @@ class ExperimentalOpenAI(BaseModel):
         "", description="Azure OpenAI deployment id, ignored when api type is openai"
     )
 
+    @validator("api_base")
+    def validate_api_base(cls, value: str):
+        if value == "https://api.openai.com/":
+            return "https://api.openai.com/v1"
+        return value
+
 
 class Config(BaseModel):
     program: Program = Program()
diff --git a/backend/src/test/models/test_config.py b/backend/src/test/models/test_config.py
new file mode 100644
index 00000000..ff4cb3f5
--- /dev/null
+++ b/backend/src/test/models/test_config.py
@@ -0,0 +1,14 @@
+from module.models.config import ExperimentalOpenAI
+
+
+def test_experimental_openai_validate_api_base():
+    config = ExperimentalOpenAI(api_type="openai", api_base="https://api.openai.com/")
+    assert config.api_base == "https://api.openai.com/v1"
+
+    config = ExperimentalOpenAI(api_base="https://api.openai.com/")
+    assert config.api_base == "https://api.openai.com/v1"
+
+    config = ExperimentalOpenAI(
+        api_type="azure", api_base="https://custom-api-base.com"
+    )
+    assert config.api_base == "https://custom-api-base.com"