diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 1f2fe5c658..198892a99e 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -3096,9 +3096,9 @@ int32_t lastFunction(SqlFunctionCtx* pCtx) {
     numOfElems++;
 
     char* data = colDataGetData(pInputCol, i);
-    TSKEY cts = *(TSKEY*) colDataGetData(pInput->pPTS, i);
-    if (pResInfo->numOfRes == 0 || pInfo->ts < cts) {
-      doSaveCurrentVal(pCtx, i, cts, type, data);
+    TSKEY* cts = (TSKEY*) colDataGetData(pInput->pPTS, i);
+    if (pResInfo->numOfRes == 0 || pInfo->ts < (*cts)) {
+      doSaveCurrentVal(pCtx, i, *cts, type, data);
       pResInfo->numOfRes = 1;
     }
   }