diff --git a/src/openai/types/beta/realtime/session_update_event.py b/src/openai/types/beta/realtime/session_update_event.py
index 11929ab376..54fd343fa6 100644
--- a/src/openai/types/beta/realtime/session_update_event.py
+++ b/src/openai/types/beta/realtime/session_update_event.py
@@ -224,13 +224,16 @@ class Session(BaseModel):
     """
 
     model: Optional[
-        Literal[
-            "gpt-4o-realtime-preview",
-            "gpt-4o-realtime-preview-2024-10-01",
-            "gpt-4o-realtime-preview-2024-12-17",
-            "gpt-4o-realtime-preview-2025-06-03",
-            "gpt-4o-mini-realtime-preview",
-            "gpt-4o-mini-realtime-preview-2024-12-17",
+        Union[
+            Literal[
+                "gpt-4o-realtime-preview",
+                "gpt-4o-realtime-preview-2024-10-01",
+                "gpt-4o-realtime-preview-2024-12-17",
+                "gpt-4o-realtime-preview-2025-06-03",
+                "gpt-4o-mini-realtime-preview",
+                "gpt-4o-mini-realtime-preview-2024-12-17",
+            ],
+            str,
         ]
     ] = None
     """The Realtime model used for this session."""