diff --git a/backend/open_webui/utils/oauth.py b/backend/open_webui/utils/oauth.py
index de3355859..6c98ed7df 100644
--- a/backend/open_webui/utils/oauth.py
+++ b/backend/open_webui/utils/oauth.py
@@ -538,7 +538,7 @@ class OAuthManager:
         # Redirect back to the frontend with the JWT token
 
         redirect_base_url = request.app.state.config.WEBUI_URL or request.base_url
-        if redirect_base_url.endswith("/"):
+        if isinstance(redirect_base_url, str) and redirect_base_url.endswith("/"):
             redirect_base_url = redirect_base_url[:-1]
         redirect_url = f"{redirect_base_url}/auth#token={jwt_token}"