diff --git a/src/main/java/com/eprosima/fastcdr/idl/templates/TypesHeader.stg b/src/main/java/com/eprosima/fastcdr/idl/templates/TypesHeader.stg
index d3b83b03..5e12f21a 100644
--- a/src/main/java/com/eprosima/fastcdr/idl/templates/TypesHeader.stg
+++ b/src/main/java/com/eprosima/fastcdr/idl/templates/TypesHeader.stg
@@ -296,9 +296,23 @@ public:
     eProsima_user_DllExport $union.name$()
     {
         $if(union.defaultAnnotatedMember)$
-        $union.defaultAnnotatedMember.name$_();
+        selected_member_ = $union.defaultAnnotatedMember.id$;
+        $if(union.defaultAnnotatedMember.typecode.primitive)$
+        member_destructor_ = nullptr;
+        m_$union.defaultAnnotatedMember.name$ = $member_default_init(union.defaultAnnotatedMember)$;
+        $else$
+        member_destructor_ = [&]() {$union_member_destroy_call(union.defaultAnnotatedMember)$\};
+        new(&m_$union.defaultAnnotatedMember.name$) $member_type_declaration(union.defaultAnnotatedMember)$();
+        $endif$;
         $elseif(union.defaultMember)$
-        $union.defaultMember.name$_();
+        selected_member_ = $union.defaultMember.id$;
+        $if(union.defaultMember.typecode.primitive)$
+        member_destructor_ = nullptr;
+        m_$union.defaultMember.name$ = $member_default_init(union.defaultMember)$;
+        $else$
+        member_destructor_ = [&]() {$union_member_destroy_call(union.defaultMember)$\};
+        new(&m_$union.defaultMember.name$) $member_type_declaration(union.defaultMember)$();
+        $endif$;
         $endif$
     }