diff --git a/include/mruby/class.h b/include/mruby/class.h
index de0846897..997486c66 100644
--- a/include/mruby/class.h
+++ b/include/mruby/class.h
@@ -79,8 +79,8 @@ mrb_class(mrb_state *mrb, mrb_value v)
 #define MRB_UNDEF_ALLOCATOR(c) (mrb_assert((c)->tt == MRB_TT_CLASS), (c)->flags |= MRB_FL_UNDEF_ALLOCATE)
 #define MRB_UNDEF_ALLOCATOR_P(c) ((c)->flags & MRB_FL_UNDEF_ALLOCATE)
 #define MRB_DEFINE_ALLOCATOR(c) ((c)->flags &= ~MRB_FL_UNDEF_ALLOCATE)
-#define MRB_SET_VISIBILITY(c,v) ((c)->flags = (((c)->flags & ~(0x3<<7)) | (((v)&0x3)<<7)))
-#define MRB_VISIBILITY(c) (((c)->flags>>7) & 0x3)
+#define MRB_CLASS_SET_VISIBILITY(c,v) ((c)->flags = (((c)->flags & ~(0x3<<7)) | (((v)&0x3)<<7)))
+#define MRB_CLASS_VISIBILITY(c) (((c)->flags>>7) & 0x3)
 
 MRB_API void mrb_define_method_raw(mrb_state*, struct RClass*, mrb_sym, mrb_method_t);
 MRB_API void mrb_alias_method(mrb_state*, struct RClass *c, mrb_sym a, mrb_sym b);
diff --git a/src/class.c b/src/class.c
index c57a12384..ba66d4360 100644
--- a/src/class.c
+++ b/src/class.c
@@ -353,7 +353,7 @@ setup_class(mrb_state *mrb, struct RClass *outer, struct RClass *c, mrb_sym id)
 {
   mrb_class_name_class(mrb, outer, c, id);
   mrb_obj_iv_set(mrb, (struct RObject*)outer, id, mrb_obj_value(c));
-  MRB_SET_VISIBILITY(c, MT_PUBLIC);
+  MRB_CLASS_SET_VISIBILITY(c, MT_PUBLIC);
 }
 
 #define make_metaclass(mrb, c) prepare_singleton_class((mrb), (struct RBasic*)(c))
@@ -787,7 +787,7 @@ mrb_define_method_raw(mrb_state *mrb, struct RClass *c, mrb_sym mid, mrb_method_
     flags = (flags & ~MT_VMASK) | MT_PRIVATE;
   }
   else if ((flags & MT_VMASK) == 0) {
-    flags |= MRB_VISIBILITY(c);
+    flags |= MRB_CLASS_VISIBILITY(c);
   }
   mt_put(mrb, h, mid, flags, ptr);
   mc_clear_by_id(mrb, mid);
@@ -1673,7 +1673,7 @@ mrb_mod_visibility(mrb_state *mrb, mrb_value mod, int visibility)
 
   mrb_get_args(mrb, "*!", &argv, &argc);
   if (argc == 0) {
-    MRB_SET_VISIBILITY(c, visibility);
+    MRB_CLASS_SET_VISIBILITY(c, visibility);
   }
   else {
     mt_tbl *h = c->mt;
diff --git a/src/vm.c b/src/vm.c
index 09ae7c651..a5434c599 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1011,7 +1011,7 @@ mrb_mod_module_eval(mrb_state *mrb, mrb_value mod)
   if (mrb_get_args(mrb, "|S&", &a, &b) == 1) {
     mrb_raise(mrb, E_NOTIMP_ERROR, "module_eval/class_eval with string not implemented");
   }
-  MRB_SET_VISIBILITY(mrb_class_ptr(mod), MRB_METHOD_PUBLIC_FL);
+  MRB_CLASS_SET_VISIBILITY(mrb_class_ptr(mod), MRB_METHOD_PUBLIC_FL);
   return eval_under(mrb, mod, b, mrb_class_ptr(mod));
 }
 
@@ -2942,7 +2942,7 @@ RETRY_TRY_BLOCK:
       const mrb_irep *nirep = irep->reps[b];
 
       /* restore visibility */
-      MRB_SET_VISIBILITY(c, MRB_METHOD_PUBLIC_FL);
+      MRB_CLASS_SET_VISIBILITY(c, MRB_METHOD_PUBLIC_FL);
 
       /* prepare closure */
       struct RProc *p = mrb_proc_new(mrb, nirep);