diff --git a/app/api/schemas/openai.py b/app/api/schemas/openai.py
index 60d8d20..f54edbd 100644
--- a/app/api/schemas/openai.py
+++ b/app/api/schemas/openai.py
@@ -59,7 +59,7 @@ def __init__(self, **data: Any):
 
 class ChatMessage(BaseModel):
     role: str
-    content: list[OpenAIContentModel] | str
+    content: list[OpenAIContentModel] | str | None = None
     name: str | None = None