diff --git a/lightrag/lightrag.py b/lightrag/lightrag.py
index 2c51fdd0..25385404 100644
--- a/lightrag/lightrag.py
+++ b/lightrag/lightrag.py
@@ -1026,7 +1026,7 @@ class LightRAG:
 
                             # Persistent llm cache
                             if self.llm_response_cache:
-                                await self.llm_response_cache.index_done_callback
+                                await self.llm_response_cache.index_done_callback()
 
                             # Update document status to failed
                             await self.doc_status.upsert(
@@ -1106,7 +1106,7 @@ class LightRAG:
 
                             # Persistent llm cache
                             if self.llm_response_cache:
-                                await self.llm_response_cache.index_done_callback
+                                await self.llm_response_cache.index_done_callback()
 
                             # Update document status to failed
                             await self.doc_status.upsert(