diff --git a/ChangeLog b/ChangeLog
index ef5c08a9ed..40cb52b808 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Dec 20 18:35:36 2012  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* gc.h (SET_MACHINE_STACK_END): add volatile for preventing
+	  harmful optimization.  [ruby-dev:46665] [Bug #7468]
+
 Thu Dec 20 18:34:38 2012  Hiroshi Shirosaki  <h.shirosaki@gmail.com>
 
 	* compile.c (ADD_CATCH_ENTRY): add a cast to fix SEGV with x64 mingw
diff --git a/gc.h b/gc.h
index f280a460ed..08ee62ad13 100644
--- a/gc.h
+++ b/gc.h
@@ -3,9 +3,9 @@
 #define RUBY_GC_H 1
 
 #if defined(__x86_64__) && defined(__GNUC__)
-#define SET_MACHINE_STACK_END(p) __asm__("movq\t%%rsp, %0" : "=r" (*(p)))
+#define SET_MACHINE_STACK_END(p) __asm__ volatile ("movq\t%%rsp, %0" : "=r" (*(p)))
 #elif defined(__i386) && defined(__GNUC__)
-#define SET_MACHINE_STACK_END(p) __asm__("movl\t%%esp, %0" : "=r" (*(p)))
+#define SET_MACHINE_STACK_END(p) __asm__ volatile ("movl\t%%esp, %0" : "=r" (*(p)))
 #else
 NOINLINE(void rb_gc_set_stack_end(VALUE **stack_end_p));
 #define SET_MACHINE_STACK_END(p) rb_gc_set_stack_end(p)
diff --git a/version.h b/version.h
index 2ee7ca9198..5bdaadf500 100644
--- a/version.h
+++ b/version.h
@@ -1,5 +1,5 @@
 #define RUBY_VERSION "1.9.3"
-#define RUBY_PATCHLEVEL 347
+#define RUBY_PATCHLEVEL 348
 
 #define RUBY_RELEASE_DATE "2012-12-20"
 #define RUBY_RELEASE_YEAR 2012