diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 1bb27780bcacd4562957d05da49c607316eb6074..280f0217b9ae934733266692400c5a38dfd04ed5 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -2471,8 +2471,8 @@ int32_t firstLastFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
   pResInfo->isNullRes = (pResInfo->numOfRes == 0) ? 1 : 0;
 
-  char* in = GET_ROWCELL_INTERBUF(pResInfo);
-  colDataAppend(pCol, pBlock->info.rows, in, pResInfo->isNullRes);
+  SFirstLastRes* pRes = GET_ROWCELL_INTERBUF(pResInfo);
+  colDataAppend(pCol, pBlock->info.rows, pRes->buf, pResInfo->isNullRes);
 
   return pResInfo->numOfRes;
 }