diff --git a/include/mruby/internal.h b/include/mruby/internal.h
index b8387b303..0c719ce27 100644
--- a/include/mruby/internal.h
+++ b/include/mruby/internal.h
@@ -176,11 +176,12 @@ size_t mrb_obj_iv_tbl_memsize(mrb_value);
 mrb_value mrb_obj_iv_inspect(mrb_state*, struct RObject*);
 void mrb_obj_iv_set_force(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v);
 mrb_value mrb_mod_constants(mrb_state *mrb, mrb_value mod);
+mrb_value mrb_mod_const_at(mrb_state *mrb, struct RClass *c, mrb_value ary);
 mrb_value mrb_f_global_variables(mrb_state *mrb, mrb_value self);
 mrb_value mrb_obj_instance_variables(mrb_state*, mrb_value);
 mrb_value mrb_mod_class_variables(mrb_state*, mrb_value);
-mrb_value mrb_mod_cv_get(mrb_state *mrb, struct RClass * c, mrb_sym sym);
-mrb_bool mrb_mod_cv_defined(mrb_state *mrb, struct RClass * c, mrb_sym sym);
+mrb_value mrb_mod_cv_get(mrb_state *mrb, struct RClass *c, mrb_sym sym);
+mrb_bool mrb_mod_cv_defined(mrb_state *mrb, struct RClass *c, mrb_sym sym);
 mrb_bool mrb_ident_p(const char *s, mrb_int len);
 mrb_value mrb_exc_const_get(mrb_state *mrb, mrb_sym sym);
 
diff --git a/src/variable.c b/src/variable.c
index ce55952af..c72093dfa 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -924,6 +924,13 @@ const_i(mrb_state *mrb, mrb_sym sym, mrb_value v, void *p)
   return 0;
 }
 
+mrb_value
+mrb_mod_const_at(mrb_state *mrb, struct RClass *c, mrb_value ary)
+{
+  iv_foreach(mrb, class_iv_ptr(c), const_i, &ary);
+  return ary;
+}
+
 /* 15.2.2.4.24 */
 /*
  *  call-seq:
@@ -941,7 +948,7 @@ mrb_mod_constants(mrb_state *mrb, mrb_value mod)
   mrb_get_args(mrb, "|b", &inherit);
   ary = mrb_ary_new(mrb);
   while (c) {
-    iv_foreach(mrb, class_iv_ptr(c), const_i, &ary);
+    mrb_mod_const_at(mrb, c, ary);
     if (!inherit) break;
     c = c->super;
     if (c == mrb->object_class) break;