diff --git a/include/mruby/value.h b/include/mruby/value.h
index 7a2b00ae5..21d32cae8 100644
--- a/include/mruby/value.h
+++ b/include/mruby/value.h
@@ -194,7 +194,6 @@ struct RObject {
   struct iv_tbl *iv;
 };
 
-#define mrb_obj_ptr(v)   ((struct RObject*)((v).value.p))
 #define mrb_immediate_p(x) (mrb_type(x) <= MRB_TT_MAIN)
 #define mrb_special_const_p(x) mrb_immediate_p(x)
 
diff --git a/src/kernel.c b/src/kernel.c
index 7187a125d..4c37b3418 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -53,7 +53,7 @@ mrb_value
 mrb_obj_inspect(mrb_state *mrb, mrb_value obj)
 {
   if ((mrb_type(obj) == MRB_TT_OBJECT) && mrb_obj_basic_to_s_p(mrb, obj)) {
-    return mrb_obj_iv_inspect(mrb, mrb_obj_ptr(obj));
+    return mrb_obj_iv_inspect(mrb, mrb_object(obj));
   }
   else if (mrb_type(obj) == MRB_TT_MAIN) {
     return mrb_str_new(mrb, "main", 4);
@@ -588,7 +588,7 @@ mrb_obj_ivar_defined(mrb_state *mrb, mrb_value self)
 
   mrb_get_args(mrb, "n", &mid);
   check_iv_name(mrb, mid);
-  if (mrb_obj_iv_defined(mrb, mrb_obj_ptr(self), mid))
+  if (mrb_obj_iv_defined(mrb, mrb_object(self), mid))
     return mrb_true_value();
   return mrb_false_value();
 }
@@ -929,7 +929,7 @@ mrb_f_raise(mrb_state *mrb, mrb_value self)
     /* fall through */
   default:
     exc = mrb_make_exception(mrb, argc, a);
-    mrb_obj_iv_set(mrb, mrb_obj_ptr(exc), mrb_intern(mrb, "lastpc"), mrb_voidp_value(mrb->ci->pc));
+    mrb_obj_iv_set(mrb, mrb_object(exc), mrb_intern(mrb, "lastpc"), mrb_voidp_value(mrb->ci->pc));
     mrb_exc_raise(mrb, exc);
   }
   return mrb_nil_value();            /* not reached */
diff --git a/src/variable.c b/src/variable.c
index 4202981a4..cf09faa88 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -438,7 +438,7 @@ mrb_value
 mrb_iv_get(mrb_state *mrb, mrb_value obj, mrb_sym sym)
 {
   if (obj_iv_p(obj)) {
-    return mrb_obj_iv_get(mrb, mrb_obj_ptr(obj), sym);
+    return mrb_obj_iv_get(mrb, mrb_object(obj), sym);
   }
   return mrb_nil_value();
 }
@@ -474,7 +474,7 @@ void
 mrb_iv_set(mrb_state *mrb, mrb_value obj, mrb_sym sym, mrb_value v)
 {
   if (obj_iv_p(obj)) {
-    mrb_obj_iv_set(mrb, mrb_obj_ptr(obj), sym, v);
+    mrb_obj_iv_set(mrb, mrb_object(obj), sym, v);
   }
   else {
     mrb_raise(mrb, E_ARGUMENT_ERROR, "cannot set instance variable");
@@ -497,14 +497,14 @@ int
 mrb_iv_defined(mrb_state *mrb, mrb_value obj, mrb_sym sym)
 {
   if (!obj_iv_p(obj)) return FALSE;
-  return mrb_obj_iv_defined(mrb, mrb_obj_ptr(obj), sym);
+  return mrb_obj_iv_defined(mrb, mrb_object(obj), sym);
 }
 
 void
 mrb_iv_copy(mrb_state *mrb, mrb_value dest, mrb_value src)
 {
-  struct RObject *d = mrb_obj_ptr(dest);
-  struct RObject *s = mrb_obj_ptr(src);
+  struct RObject *d = mrb_object(dest);
+  struct RObject *s = mrb_object(src);
 
   if (d->iv) {
     iv_free(mrb, d->iv);
@@ -558,7 +558,7 @@ mrb_value
 mrb_iv_remove(mrb_state *mrb, mrb_value obj, mrb_sym sym)
 {
   if (obj_iv_p(obj)) {
-    iv_tbl *t = mrb_obj_ptr(obj)->iv;
+    iv_tbl *t = mrb_object(obj)->iv;
     mrb_value val;
 
     if (t && iv_del(mrb, t, sym, &val)) {
@@ -620,8 +620,8 @@ mrb_obj_instance_variables(mrb_state *mrb, mrb_value self)
   mrb_value ary;
 
   ary = mrb_ary_new(mrb);
-  if (obj_iv_p(self) && mrb_obj_ptr(self)->iv) {
-    iv_foreach(mrb, mrb_obj_ptr(self)->iv, iv_i, &ary);
+  if (obj_iv_p(self) && mrb_object(self)->iv) {
+    iv_foreach(mrb, mrb_object(self)->iv, iv_i, &ary);
   }
   return ary;
 }
@@ -663,8 +663,8 @@ mrb_mod_class_variables(mrb_state *mrb, mrb_value mod)
   mrb_value ary;
 
   ary = mrb_ary_new(mrb);
-  if (obj_iv_p(mod) && mrb_obj_ptr(mod)->iv) {
-    iv_foreach(mrb, mrb_obj_ptr(mod)->iv, cv_i, &ary);
+  if (obj_iv_p(mod) && mrb_object(mod)->iv) {
+    iv_foreach(mrb, mrb_object(mod)->iv, cv_i, &ary);
   }
   return ary;
 }