diff --git a/ChangeLog b/ChangeLog
index bf91651562..71a8ed5a8f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Mar 18 10:41:06 2013  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* vm_exec.c: Correct predefined macro name. This typo is introduced by
+	  r36534 and should be backported to ruby_2_0_0.
+
 Mon Mar 18 03:18:00 2013  Zachary Scott  <zachary@zacharyscott.net>
 
 	* array.c: Typo in Array#delete by Timo Sand [GH fixes #258]
diff --git a/vm_exec.c b/vm_exec.c
index 489181cdff..c914a8bcca 100644
--- a/vm_exec.c
+++ b/vm_exec.c
@@ -18,7 +18,7 @@ static void vm_analysis_insn(int insn);
 #if VMDEBUG > 0
 #define DECL_SC_REG(type, r, reg) register type reg_##r
 
-#elif defined(__GNUC__) && defined(_x86_64__)
+#elif defined(__GNUC__) && defined(__x86_64__)
 #define DECL_SC_REG(type, r, reg) register type reg_##r __asm__("r" reg)
 
 #elif defined(__GNUC__) && defined(__i386__)