1 files changed, 3 insertions, 5 deletions
diff --git a/src/etc.c b/src/etc.c
index 5d2c836e7..0b58ad67c 100644
--- a/src/etc.c
+++ b/src/etc.c
@@ -37,14 +37,13 @@ mrb_get_datatype(mrb_state *mrb, mrb_value obj, const mrb_data_type *type)
 void *
 mrb_check_datatype(mrb_state *mrb, mrb_value obj, const mrb_data_type *type)
 {
-  static const char mesg[] = "wrong argument type %s (expected %s)";
-
   if (mrb_special_const_p(obj) || (mrb_type(obj) != MRB_TT_DATA)) {
     mrb_check_type(mrb, obj, MRB_TT_DATA);
   }
   if (DATA_TYPE(obj) != type) {
     const char *etype = DATA_TYPE(obj)->struct_name;
-    mrb_raisef(mrb, E_TYPE_ERROR, mesg, etype, type->struct_name);
+    mrb_raisef(mrb, E_TYPE_ERROR, "wrong argument type %S (expected %S)",
+               mrb_str_new_cstr(mrb, etype), mrb_str_new_cstr(mrb, type->struct_name));
   }
   return DATA_PTR(obj);
 }
@@ -93,8 +92,7 @@ mrb_to_id(mrb_state *mrb, mrb_value name)
       tmp = mrb_check_string_type(mrb, name);
       if (mrb_nil_p(tmp)) {
         tmp = mrb_inspect(mrb, name);
-        mrb_raisef(mrb, E_TYPE_ERROR, "%s is not a symbol",
-             RSTRING_PTR(tmp));
+        mrb_raisef(mrb, E_TYPE_ERROR, "%S is not a symbol", tmp);
       }
       name = tmp;
       /* fall through */