diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index c843de2b941e5685f020968ae74a10fb5fd16f06..9085f00b290a5c0202406bb87a9eaede77bb9ff5 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -1168,7 +1168,7 @@ static int32_t findRowIndex(int32_t start, int32_t num, SColumnInfoData* pCol, c
     }
   }
 
-  // if reach here means real data of block SMA is not set.
+  // if reach here means real data of block SMA is not set in pCtx->input.
   return -1;
 }