diff --git a/sql/sql_string.cc b/sql/sql_string.cc
index b222d3394eb..c05a7b85f77 100644
--- a/sql/sql_string.cc
+++ b/sql/sql_string.cc
@@ -203,6 +203,7 @@ bool String::copy(const String &str)
   str_length=str.str_length;
   bmove(Ptr,str.Ptr,str_length);		// May be overlapping
   Ptr[str_length]=0;
+  str_charset=str.str_charset;
   return FALSE;
 }
 
diff --git a/sql/sql_string.h b/sql/sql_string.h
index 68c5e005782..5e5c9001590 100644
--- a/sql/sql_string.h
+++ b/sql/sql_string.h
@@ -46,6 +46,7 @@ public:
   String(uint32 length_arg)
   { 
     alloced=0; Alloced_length=0; (void) real_alloc(length_arg); 
+    str_charset=default_charset_info;
   }
   String(const char *str, CHARSET_INFO *cs)
   {