diff --git a/dbms/src/DataTypes/tests/gtest_data_type_get_common_type.cpp b/dbms/src/DataTypes/tests/gtest_data_type_get_common_type.cpp
index 2ae1c335387..cb104660cec 100644
--- a/dbms/src/DataTypes/tests/gtest_data_type_get_common_type.cpp
+++ b/dbms/src/DataTypes/tests/gtest_data_type_get_common_type.cpp
@@ -14,7 +14,7 @@ static bool operator==(const IDataType & left, const IDataType & right)
     return left.equals(right);
 }
 
-static std::ostream & operator<<(std::ostream & ostr, const IDataType & dt)
+std::ostream & operator<<(std::ostream & ostr, const IDataType & dt)
 {
     return ostr << dt.getName();
 }