diff --git a/source/libs/parser/src/astValidate.c b/source/libs/parser/src/astValidate.c
index 9c3537e261..545f2dd838 100644
--- a/source/libs/parser/src/astValidate.c
+++ b/source/libs/parser/src/astValidate.c
@@ -3137,7 +3137,7 @@ int32_t  sqlExprToExprNode(tExprNode **pExpr, const tSqlExpr* pSqlExpr, SQuerySt
     }
 
   } else {
-    *pExpr = (tExprNode *)calloc(1, sizeof(tExprNode));
+    *pExpr = (tExprNode*)calloc(1, sizeof(tExprNode));
     (*pExpr)->nodeType = TEXPR_BINARYEXPR_NODE;
 
     (*pExpr)->_node.pLeft = pLeft;
@@ -3158,9 +3158,16 @@ int32_t  sqlExprToExprNode(tExprNode **pExpr, const tSqlExpr* pSqlExpr, SQuerySt
     }
 
     // scalar op aggregate check
+    if (pLeft->nodeType == TEXPR_FUNCTION_NODE && pRight->nodeType != TEXPR_FUNCTION_NODE) {
+      return buildInvalidOperationMsg(pMsgBuf, "invalid expression");
+    }
 
+    if (pLeft->nodeType == TEXPR_FUNCTION_NODE && pRight->nodeType == TEXPR_FUNCTION_NODE) {
+      if (qIsAggregateFunction(pLeft->_function.functionName) != qIsAggregateFunction(pRight->_function.functionName)) {
+        return buildInvalidOperationMsg(pMsgBuf, "invalid expression");
+      }
+    }
   }
-
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/source/libs/parser/test/parserTests.cpp b/source/libs/parser/test/parserTests.cpp
index 00a31dc89d..45b8a3627b 100644
--- a/source/libs/parser/test/parserTests.cpp
+++ b/source/libs/parser/test/parserTests.cpp
@@ -406,8 +406,8 @@ TEST(testCase, function_Test10) {
   sqlCheck("select cov(a, b) from `t.1abc`", true);
   sqlCheck("select sum(length(a) + count(b)) from `t.1abc`", false);
 
-  //  sqlCheck("select concat(concat(a,b), concat(a,b)) from `t.1abc`", true);
-  //  sqlCheck("select length(length(length(a))) from `t.1abc`", true);
+    sqlCheck("select concat(concat(a,b), concat(a,b)) from `t.1abc`", true);
+    sqlCheck("select length(length(length(a))) from `t.1abc`", true);
 }
 
 TEST(testCase, function_Test6) {