diff --git a/api/apps/conversation_app.py b/api/apps/conversation_app.py
index 09245bc0897..e07a46da339 100644
--- a/api/apps/conversation_app.py
+++ b/api/apps/conversation_app.py
@@ -187,6 +187,8 @@ def get_value(d, k1, k2):
                 return d.get(k1, d.get(k2))
 
             for ref in conv.reference:
+                if isinstance(ref, list):
+                    continue
                 ref["chunks"] = [{
                     "id": get_value(ck, "chunk_id", "id"),
                     "content": get_value(ck, "content", "content_with_weight"),