diff --git a/api/core/workflow/graph_engine/graph_engine.py b/api/core/workflow/graph_engine/graph_engine.py
index 80e2cf6899..d11994dc9c 100644
--- a/api/core/workflow/graph_engine/graph_engine.py
+++ b/api/core/workflow/graph_engine/graph_engine.py
@@ -85,7 +85,10 @@ class GraphEngine:
             # run graph
             generator = self._run(start_node_id=self.graph.root_node_id)
             if self.init_params.workflow_type == WorkflowType.CHAT:
-                answer_stream_processor = AnswerStreamProcessor(self.graph)
+                answer_stream_processor = AnswerStreamProcessor(
+                    graph=self.graph,
+                    variable_pool=self.graph_runtime_state.variable_pool
+                )
                 generator = answer_stream_processor.process(generator)
 
             for item in generator: