diff --git a/rag/prompts/generator.py b/rag/prompts/generator.py
index b9c2113d8f..3037e0c4a3 100644
--- a/rag/prompts/generator.py
+++ b/rag/prompts/generator.py
@@ -40,6 +40,9 @@ def get_value(d, k1, k2):
 def chunks_format(reference):
     if not reference or not isinstance(reference, dict):
         return []
+    raw_chunks = reference.get("chunks", [])
+    if not isinstance(raw_chunks, list):
+        return []
     return [
         {
             "id": get_value(chunk, "chunk_id", "id"),
@@ -55,7 +58,8 @@ def chunks_format(reference):
             "term_similarity": chunk.get("term_similarity"),
             "doc_type": get_value(chunk, "doc_type_kwd", "doc_type"),
         }
-        for chunk in reference.get("chunks", [])
+        for chunk in raw_chunks
+        if isinstance(chunk, dict)
     ]
 
 
diff --git a/test/testcases/test_http_api/test_session_management/test_session_sdk_routes_unit.py b/test/testcases/test_http_api/test_session_management/test_session_sdk_routes_unit.py
index 6852024db3..a83a3564d4 100644
--- a/test/testcases/test_http_api/test_session_management/test_session_sdk_routes_unit.py
+++ b/test/testcases/test_http_api/test_session_management/test_session_sdk_routes_unit.py
@@ -762,7 +762,7 @@ def test_openai_nonstream_branch_unit(monkeypatch):
 
     res = _run(inspect.unwrap(module.chat_completion_openai_like)("tenant-1", "chat-1"))
     assert res["choices"][0]["message"]["content"] == "world"
-
+    
 
 @pytest.mark.p2
 def test_agents_openai_compatibility_unit(monkeypatch):