diff --git a/core/session_manager.py b/core/session_manager.py
index 0fb9b28..d8b74a3 100644
--- a/core/session_manager.py
+++ b/core/session_manager.py
@@ -33,6 +33,22 @@ class SessionManager:
         
         print(f"SessionManager initialized with Redis backend and {session_timeout_minutes}min timeout")
     
+    def __getstate__(self):
+        state = self.__dict__.copy()
+        # Exclude the unpickleable 'lock' and 'cleanup_thread' attributes
+        if 'lock' in state:
+            del state['lock']
+        if 'cleanup_thread' in state:
+            del state['cleanup_thread']
+        return state
+
+    def __setstate__(self, state):
+        self.__dict__.update(state)
+        # Re-initialize the 'lock' and 'cleanup_thread' attributes
+        self.lock = threading.Lock()
+        self.cleanup_thread = threading.Thread(target=self._cleanup_loop, daemon=True)
+        self.cleanup_thread.start()
+
     def _get_session_key(self, session_id: str) -> str:
         """Generates the Redis key for a session."""
         return f"dnsrecon:session:{session_id}"