diff --git a/dbms/src/DataTypes/DataTypeDateTime.cpp b/dbms/src/DataTypes/DataTypeDateTime.cpp
index 5589a372732..8903d3b03b3 100644
--- a/dbms/src/DataTypes/DataTypeDateTime.cpp
+++ b/dbms/src/DataTypes/DataTypeDateTime.cpp
@@ -49,7 +49,7 @@ DataTypeDateTime::DataTypeDateTime(const String & time_zone_name, const String &
 }
 
 DataTypeDateTime::DataTypeDateTime(const TimezoneMixin & time_zone_)
-    : TimezoneMixin(time_zone_)
+    : TimezoneMixin(time_zone_), type_name(family_name)
 {}
 
 String DataTypeDateTime::doGetName() const