diff --git a/backend/open_webui/socket/main.py b/backend/open_webui/socket/main.py
index 5157c3ed36..1168d5945f 100644
--- a/backend/open_webui/socket/main.py
+++ b/backend/open_webui/socket/main.py
@@ -206,7 +206,7 @@ async def periodic_session_pool_cleanup():
                     if expired:
                         log.warning('Reaping %d orphaned session(s) from the session pool', len(expired))
                         if WEBSOCKET_MANAGER == 'redis':
-                            SESSION_POOL.pop_many(*expired)
+                            SESSION_POOL.delete_many(*expired)
                         else:
                             for sid in expired:
                                 SESSION_POOL.pop(sid, None)
diff --git a/backend/open_webui/socket/utils.py b/backend/open_webui/socket/utils.py
index 3e1479bde0..323735f6f1 100644
--- a/backend/open_webui/socket/utils.py
+++ b/backend/open_webui/socket/utils.py
@@ -115,10 +115,11 @@ class RedisDict:
             if cursor == 0:
                 break
 
-    def pop_many(self, *keys):
+    def delete_many(self, *keys):
         """Delete fields in one HDEL; no keys is a no-op (HDEL rejects an empty field list)."""
         if keys:
             self.redis.hdel(self.name, *keys)
+            self._last_signature = None
 
     def set(self, mapping: dict):
         if not mapping: