diff --git a/src/cleveragents/langgraph/graph.py b/src/cleveragents/langgraph/graph.py
index a1b36ccb3..17fc46583 100644
--- a/src/cleveragents/langgraph/graph.py
+++ b/src/cleveragents/langgraph/graph.py
@@ -108,7 +108,9 @@ class LangGraph:  # pylint: disable=too-many-instance-attributes
             if isinstance(input_data, GraphState)
             else GraphState.from_dict(input_data)
         )
-        # Replace state manager state for a fresh execution context
+        # Use replace_state() so the is_closed guard is enforced and state stream
+        # subscribers are notified through the proper StateManager API, preventing
+        # silent state corruption after StateManager.close() has been called.
         self.state_manager.replace_state(state)
         start_stream = f"__{self.name}_node_start__"
         if start_stream in self.stream_router.streams: