diff --git a/api/core/workflow/nodes/answer/answer_stream_generate_router.py b/api/core/workflow/nodes/answer/answer_stream_generate_router.py
index 2562b9ce960ec3..06050e15490cbc 100644
--- a/api/core/workflow/nodes/answer/answer_stream_generate_router.py
+++ b/api/core/workflow/nodes/answer/answer_stream_generate_router.py
@@ -151,7 +151,7 @@ def _recursive_fetch_answer_dependencies(
             if source_node_type in (
                 NodeType.ANSWER.value,
                 NodeType.IF_ELSE.value,
-                NodeType.QUESTION_CLASSIFIER,
+                NodeType.QUESTION_CLASSIFIER.value,
             ):
                 answer_dependencies[answer_node_id].append(source_node_id)
             else: