diff --git a/source/libs/executor/src/dynqueryctrloperator.c b/source/libs/executor/src/dynqueryctrloperator.c
index 02932cd278..772222f9ed 100644
--- a/source/libs/executor/src/dynqueryctrloperator.c
+++ b/source/libs/executor/src/dynqueryctrloperator.c
@@ -320,7 +320,7 @@ static int32_t buildMergeJoinOperatorParam(SOperatorParam** ppRes, bool initPara
     return code;
   }
   (*ppRes)->pChildren = taosArrayInit(2, POINTER_BYTES);
-  if (NULL == *ppRes) {
+  if (NULL == (*ppRes)->pChildren) {
     code = terrno;
     freeOperatorParam(pChild0, OP_GET_PARAM);
     freeOperatorParam(pChild1, OP_GET_PARAM);