diff --git a/api/core/tools/utils/dataset_retriever/dataset_retriever_tool.py b/api/core/tools/utils/dataset_retriever/dataset_retriever_tool.py
index f661294ec4..f5838c3b76 100644
--- a/api/core/tools/utils/dataset_retriever/dataset_retriever_tool.py
+++ b/api/core/tools/utils/dataset_retriever/dataset_retriever_tool.py
@@ -94,7 +94,7 @@ class DatasetRetrieverTool(DatasetRetrieverBaseTool):
                         "title": item.metadata.get("title"),
                         "content": item.page_content,
                     }
-                context_list.append(source)
+                    context_list.append(source)
             for hit_callback in self.hit_callbacks:
                 hit_callback.return_retriever_resource_info(context_list)