diff --git a/src/mcp/server/auth/handlers/token.py b/src/mcp/server/auth/handlers/token.py
index 4e15e6265..f3e627a58 100644
--- a/src/mcp/server/auth/handlers/token.py
+++ b/src/mcp/server/auth/handlers/token.py
@@ -110,7 +110,7 @@ async def handle(self, request: Request):
         except AuthenticationError as e:
             return self.response(
                 TokenErrorResponse(
-                    error="unauthorized_client",
+                    error="invalid_client",
                     error_description=e.message,
                 )
             )