4 files changed, 10 insertions, 9 deletions
diff --git a/include/mruby/variable.h b/include/mruby/variable.h
index 8758114b9..2779304eb 100644
--- a/include/mruby/variable.h
+++ b/include/mruby/variable.h
@@ -50,7 +50,7 @@ MRB_API void mrb_iv_set(mrb_state *mrb, mrb_value obj, mrb_sym sym, mrb_value v)
 MRB_API mrb_bool mrb_iv_defined(mrb_state*, mrb_value, mrb_sym);
 MRB_API mrb_value mrb_iv_remove(mrb_state *mrb, mrb_value obj, mrb_sym sym);
 MRB_API void mrb_iv_copy(mrb_state *mrb, mrb_value dst, mrb_value src);
-MRB_API mrb_bool mrb_const_defined_at(mrb_state *mrb, struct RClass *klass, mrb_sym id);
+MRB_API mrb_bool mrb_const_defined_at(mrb_state *mrb, mrb_value mod, mrb_sym id);
 MRB_API mrb_value mrb_gv_get(mrb_state *mrb, mrb_sym sym);
 MRB_API void mrb_gv_set(mrb_state *mrb, mrb_sym sym, mrb_value val);
 MRB_API void mrb_gv_remove(mrb_state *mrb, mrb_sym sym);
diff --git a/mrbgems/mruby-struct/src/struct.c b/mrbgems/mruby-struct/src/struct.c
index 0c1016b4c..420052e4d 100644
--- a/mrbgems/mruby-struct/src/struct.c
+++ b/mrbgems/mruby-struct/src/struct.c
@@ -263,7 +263,7 @@ make_struct(mrb_state *mrb, mrb_value name, mrb_value members, struct RClass * k
     if (!is_const_id(mrb, mrb_sym2name_len(mrb, id, NULL))) {
       mrb_name_error(mrb, id, "identifier %S needs to be constant", name);
     }
-    if (mrb_const_defined_at(mrb, klass, id)) {
+    if (mrb_const_defined_at(mrb, mrb_obj_value(klass), id)) {
       mrb_warn(mrb, "redefining constant Struct::%S", name);
       /* ?rb_mod_remove_const(klass, mrb_sym2name(mrb, id)); */
     }
diff --git a/src/class.c b/src/class.c
index c11346223..63b9c3ee0 100644
--- a/src/class.c
+++ b/src/class.c
@@ -137,7 +137,7 @@ define_module(mrb_state *mrb, mrb_sym name, struct RClass *outer)
 {
   struct RClass *m;
 
-  if (mrb_const_defined_at(mrb, outer, name)) {
+  if (mrb_const_defined_at(mrb, mrb_obj_value(outer), name)) {
     return module_from_sym(mrb, outer, name);
   }
   m = mrb_module_new(mrb);
@@ -179,7 +179,7 @@ define_class(mrb_state *mrb, mrb_sym name, struct RClass *super, struct RClass *
 {
   struct RClass * c;
 
-  if (mrb_const_defined_at(mrb, outer, name)) {
+  if (mrb_const_defined_at(mrb, mrb_obj_value(outer), name)) {
     c = class_from_sym(mrb, outer, name);
     if (super && mrb_class_real(c->super) != super) {
       mrb_raisef(mrb, E_TYPE_ERROR, "superclass mismatch for Class %S (%S not %S)",
diff --git a/src/variable.c b/src/variable.c
index e9f77b8d9..c4f6fb830 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -1081,9 +1081,10 @@ mrb_f_global_variables(mrb_state *mrb, mrb_value self)
 }
 
 static mrb_bool
-mrb_const_defined_0(mrb_state *mrb, struct RClass *klass, mrb_sym id, mrb_bool exclude, mrb_bool recurse)
+mrb_const_defined_0(mrb_state *mrb, mrb_value mod, mrb_sym id, mrb_bool exclude, mrb_bool recurse)
 {
-  struct RClass * tmp;
+  struct RClass *klass = mrb_class_ptr(mod);
+  struct RClass *tmp;
   mrb_bool mod_retry = 0;
 
   tmp = klass;
@@ -1106,13 +1107,13 @@ retry:
 MRB_API mrb_bool
 mrb_const_defined(mrb_state *mrb, mrb_value mod, mrb_sym id)
 {
-  return mrb_const_defined_0(mrb, mrb_class_ptr(mod), id, TRUE, TRUE);
+  return mrb_const_defined_0(mrb, mod, id, TRUE, TRUE);
 }
 
 MRB_API mrb_bool
-mrb_const_defined_at(mrb_state *mrb, struct RClass *klass, mrb_sym id)
+mrb_const_defined_at(mrb_state *mrb, mrb_value mod, mrb_sym id)
 {
-  return mrb_const_defined_0(mrb, klass, id, TRUE, FALSE);
+  return mrb_const_defined_0(mrb, mod, id, TRUE, FALSE);
 }
 
 MRB_API mrb_value