diff --git a/ChangeLog b/ChangeLog
index b4ed3c3a20..41cbbe87fd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,7 @@
-Mon Jun 29 02:08:01 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Mon Jun 29 02:10:10 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* insns.def (defineclass): preserve encoding of name in error
+	  messages for super class mismatch.
 
 	* insns.def (defineclass): preserve encoding of name in error
 	  messages for non-class super.
diff --git a/insns.def b/insns.def
index b983140fd8..f9ff0a4f74 100644
--- a/insns.def
+++ b/insns.def
@@ -869,8 +869,8 @@ defineclass
 		tmp = rb_class_real(RCLASS_SUPER(klass));
 
 		if (tmp != super) {
-		    rb_raise(rb_eTypeError, "superclass mismatch for class %s",
-			     rb_id2name(id));
+		    rb_raise(rb_eTypeError, "superclass mismatch for class % "PRIsVALUE"",
+			     rb_id2str(id));
 		}
 	    }
 	}
diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 27558e33dd..9c016dd693 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -369,6 +369,9 @@ class TestClass < Test::Unit::TestCase
         end
       end;
     }
+    assert_raise_with_message(TypeError, /#{n}/) {
+      m.module_eval "class #{n} < Class.new; end"
+    }
   end
 
   def test_cloned_singleton_method_added