diff --git a/ChangeLog b/ChangeLog
index c3a3ab141f..cc2c57ff43 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jan 10 19:39:05 2013  TAKANO `takano32' Mitsuhiro <tak@no32.tk>
+
+	* thread.c: fix RB_GC_SAVE_MACHINE_REGISTER_STACK define for ia64.
+
 Thu Jan 10 17:45:39 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* Makefile.in, win32/Makefile.sub ($(MKFILES)): continue if Makefile
diff --git a/thread.c b/thread.c
index 37eb858d23..e2741fdd6f 100644
--- a/thread.c
+++ b/thread.c
@@ -106,7 +106,7 @@ static inline void blocking_region_end(rb_thread_t *th, struct rb_blocking_regio
 
 #ifdef __ia64
 #define RB_GC_SAVE_MACHINE_REGISTER_STACK(th)          \
-    do{(th)->machine_register_stack_end = rb_ia64_bsp()}while(0)
+    do{(th)->machine_register_stack_end = rb_ia64_bsp();}while(0)
 #else
 #define RB_GC_SAVE_MACHINE_REGISTER_STACK(th)
 #endif