diff --git a/ChangeLog b/ChangeLog
index f7a4e7c982..ed55b8fde8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Thu Mar 21 23:14:15 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/ruby.h (RB_UNUSED_VAR): move code from
+	  UNINITIALIZED_VAR() in vm_core.h.
+
+	* vm_core.h (UNINITIALIZED_VAR): use RB_UNUSED_VAR().
+
 Thu Mar 21 22:39:46 2013  Naohisa Goto  <ngotogenome@gmail.com>
 
 	* marshal.c (marshal_dump, marshal_load): workaround for segv on
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 70b6769ec0..947927ba7c 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -529,8 +529,10 @@ static inline volatile VALUE *rb_gc_guarded_ptr(volatile VALUE *ptr) {return ptr
 #endif
 #define RB_GC_GUARD(v) (*RB_GC_GUARD_PTR(&(v)))
 
-#ifdef __GNUC__
-#define RB_UNUSED_VAR(x) x __attribute__ ((unused)) 
+#if (defined(__clang__) && (__clang_major__ == 4 && __clang_minor__ == 2))
+#define RB_UNUSED_VAR(x) x __attribute__ ((unused))
+#elif defined(__GNUC__) && __GNUC__ >= 3
+#define RB_UNUSED_VAR(x) x = x
 #else
 #define RB_UNUSED_VAR(x) x
 #endif
diff --git a/vm_core.h b/vm_core.h
index 576ba8e0d9..c942c6e3e6 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -115,13 +115,7 @@
 #define UNLIKELY(x) (x)
 #endif /* __GNUC__ >= 3 */
 
-#if (defined(__clang__) && (__clang_major__ == 4 && __clang_minor__ == 2))
-#define UNINITIALIZED_VAR(x) x __attribute__((unused))
-#elif defined(__GNUC__) && __GNUC__ >= 3
-#define UNINITIALIZED_VAR(x) x = x
-#else
-#define UNINITIALIZED_VAR(x) x
-#endif
+#define UNINITIALIZED_VAR(x) RB_UNUSED_VAR(x)
 
 typedef unsigned long rb_num_t;