diff --git a/src/agent.py b/src/agent.py
index b8816291..07fd911e 100644
--- a/src/agent.py
+++ b/src/agent.py
@@ -418,12 +418,8 @@ async def async_langflow_chat(
             from services.session_ownership_service import session_ownership_service
             from services.user_binding_service import user_binding_service
             
-            # Check if this is a Google user (has binding but not UUID format)
-            import re
-            uuid_pattern = r'^[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}$'
-            is_uuid = bool(re.match(uuid_pattern, user_id.lower().replace('-', '')))
-            
-            if not is_uuid and user_binding_service.has_binding(user_id):
+            # Check if this is a Google user (Google IDs are numeric, Langflow IDs are UUID)
+            if user_id.isdigit() and user_binding_service.has_binding(user_id):
                 langflow_user_id = user_binding_service.get_langflow_user_id(user_id)
                 if langflow_user_id:
                     session_ownership_service.claim_session(user_id, response_id, langflow_user_id)
@@ -511,12 +507,8 @@ async def async_langflow_chat_stream(
                 from services.session_ownership_service import session_ownership_service
                 from services.user_binding_service import user_binding_service
                 
-                # Check if this is a Google user (has binding but not UUID format)
-                import re
-                uuid_pattern = r'^[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}$'
-                is_uuid = bool(re.match(uuid_pattern, user_id.lower().replace('-', '')))
-                
-                if not is_uuid and user_binding_service.has_binding(user_id):
+                # Check if this is a Google user (Google IDs are numeric, Langflow IDs are UUID)
+                if user_id.isdigit() and user_binding_service.has_binding(user_id):
                     langflow_user_id = user_binding_service.get_langflow_user_id(user_id)
                     if langflow_user_id:
                         session_ownership_service.claim_session(user_id, response_id, langflow_user_id)
diff --git a/src/services/langflow_history_service.py b/src/services/langflow_history_service.py
index e6e49f4d..ad17a238 100644
--- a/src/services/langflow_history_service.py
+++ b/src/services/langflow_history_service.py
@@ -44,11 +44,9 @@ class LangflowHistoryService:
         return None
         
     def _is_uuid_format(self, user_id: str) -> bool:
-        """Check if string looks like a UUID (Langflow user ID format)"""
-        import re
-        # Basic UUID pattern check (with or without dashes)
-        uuid_pattern = r'^[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}$'
-        return bool(re.match(uuid_pattern, user_id.lower().replace('-', '')))
+        """Check if string looks like a UUID (Langflow user ID format vs Google numeric ID)"""
+        # Langflow IDs are UUID v4, Google IDs are purely numeric
+        return not user_id.isdigit()
         
     def _filter_sessions_by_ownership(self, session_ids: List[str], user_id: str, langflow_user_id: str) -> List[str]:
         """Filter sessions based on user type and ownership"""
diff --git a/src/services/user_binding_service.py b/src/services/user_binding_service.py
index 4cead0aa..b7bbe905 100644
--- a/src/services/user_binding_service.py
+++ b/src/services/user_binding_service.py
@@ -237,11 +237,9 @@ class UserBindingService:
         return self.bindings.copy()
         
     def is_langflow_user_id(self, user_id: str) -> bool:
-        """Check if user_id appears to be a Langflow UUID"""
-        import re
-        # Basic UUID pattern check (with or without dashes)
-        uuid_pattern = r'^[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}$'
-        return bool(re.match(uuid_pattern, user_id.lower().replace('-', '')))
+        """Check if user_id appears to be a Langflow UUID (vs Google numeric ID)"""
+        # Langflow IDs are UUID v4, Google IDs are purely numeric
+        return not user_id.isdigit()
         
     def get_user_type(self, user_id: str) -> str:
         """Determine user type: 'google_oauth', 'langflow_direct', or 'unknown'"""