diff --git a/ChangeLog b/ChangeLog
index f7e7552923..3f884a415f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Feb 26 21:29:48 2010  Tanaka Akira  <akr@fsij.org>
+
+	* configure.in (RSHIFT): add parenthesis to supress warning.
+
 Fri Feb 26 20:51:47 2010  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* ext/socket/raddrinfo.c, ext/socket/udpsocket.c: avoid illegal cast
diff --git a/configure.in b/configure.in
index 4542bda2e4..6d247fdb96 100644
--- a/configure.in
+++ b/configure.in
@@ -1341,9 +1341,9 @@ AC_CACHE_CHECK(whether right shift preserve sign bit, rb_cv_rshift_sign,
 	rb_cv_rshift_sign=yes,
 	rb_cv_rshift_sign=no)])
 if test "$rb_cv_rshift_sign" = yes; then
-  AC_DEFINE(RSHIFT(x,y), ((x)>>(int)y))
+  AC_DEFINE(RSHIFT(x,y), ((x)>>((int)y)))
 else
-  AC_DEFINE(RSHIFT(x,y), (((x)<0) ? ~((~(x))>>y) : (x)>>y))
+  AC_DEFINE(RSHIFT(x,y), (((x)<0) ? ~((~(x))>>(y)) : (x)>>(y)))
 fi
 
 AC_MSG_CHECKING(read count field in FILE structures)