diff --git a/dbms/src/DataTypes/DataTypeDomainSimpleAggregateFunction.cpp b/dbms/src/DataTypes/DataTypeDomainSimpleAggregateFunction.cpp
index 570310c1312..ee524f76ec9 100644
--- a/dbms/src/DataTypes/DataTypeDomainSimpleAggregateFunction.cpp
+++ b/dbms/src/DataTypes/DataTypeDomainSimpleAggregateFunction.cpp
@@ -70,18 +70,18 @@ static std::pair<DataTypePtr, DataTypeDomainPtr> create(const ASTPtr & arguments
         throw Exception("Data type SimpleAggregateFunction requires parameters: "
                         "name of aggregate function and list of data types for arguments", ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
 
-    if (const ASTFunction * parametric = typeid_cast<const ASTFunction *>(arguments->children[0].get()))
+    if (const ASTFunction * parametric = arguments->children[0]->as<ASTFunction>())
     {
         if (parametric->parameters)
             throw Exception("Unexpected level of parameters to aggregate function", ErrorCodes::SYNTAX_ERROR);
         function_name = parametric->name;
 
-        const ASTs & parameters = typeid_cast<const ASTExpressionList &>(*parametric->arguments).children;
+        const ASTs & parameters = parametric->arguments->as<ASTExpressionList &>().children;
         params_row.resize(parameters.size());
 
         for (size_t i = 0; i < parameters.size(); ++i)
         {
-            const ASTLiteral * lit = typeid_cast<const ASTLiteral *>(parameters[i].get());
+            const ASTLiteral * lit = parameters[i]->as<ASTLiteral>();
             if (!lit)
                 throw Exception("Parameters to aggregate functions must be literals",
                                 ErrorCodes::PARAMETERS_TO_AGGREGATE_FUNCTIONS_MUST_BE_LITERALS);
@@ -93,7 +93,7 @@ static std::pair<DataTypePtr, DataTypeDomainPtr> create(const ASTPtr & arguments
     {
         function_name = *opt_name;
     }
-    else if (typeid_cast<ASTLiteral *>(arguments->children[0].get()))
+    else if (arguments->children[0]->as<ASTLiteral>())
     {
         throw Exception("Aggregate function name for data type SimpleAggregateFunction must be passed as identifier (without quotes) or function",
                         ErrorCodes::BAD_ARGUMENTS);