diff --git a/backend/open_webui/routers/openai.py b/backend/open_webui/routers/openai.py
index 5b54796a70..62b6dedf0a 100644
--- a/backend/open_webui/routers/openai.py
+++ b/backend/open_webui/routers/openai.py
@@ -95,7 +95,7 @@ async def cleanup_response(
         await session.close()
 
 
-def openai_o_series_handler(payload):
+def openai_reasoning_model_handler(payload):
     """
     Handle "o" series specific parameters
     """
@@ -788,9 +788,9 @@ async def generate_chat_completion(
     key = request.app.state.config.OPENAI_API_KEYS[idx]
 
     # Check if model is from "o" series
-    is_o_series = payload["model"].lower().startswith(("o1", "o3", "o4"))
-    if is_o_series:
-        payload = openai_o_series_handler(payload)
+    is_reasoning_model = payload["model"].lower().startswith(("o1", "o3", "o4", "gpt-5"))
+    if is_reasoning_model:
+        payload = openai_reasoning_model_handler(payload)
     elif "api.openai.com" not in url:
         # Remove "max_completion_tokens" from the payload for backward compatibility
         if "max_completion_tokens" in payload: