diff --git a/ChangeLog b/ChangeLog
index 0ac00c69c4..5872e7b7cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Oct  9 16:54:28 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in (RSHIFT): quote to get rid of argument expansion
+	  for autoconf 2.68.
+
 Sat Oct  9 11:00:06 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* thread.c (thread_reset_event_flags, exec_event_hooks): ignore
diff --git a/configure.in b/configure.in
index c7d257c995..158a7e65d1 100644
--- a/configure.in
+++ b/configure.in
@@ -1475,7 +1475,7 @@ if test x"$target_cpu" = xia64; then
 fi
 
 AC_CACHE_CHECK(whether right shift preserve sign bit, rb_cv_rshift_sign,
-    [AC_COMPILE_IFELSE(AC_LANG_BOOL_COMPILE_TRY([], [(-1==(-1>>1))]),
+    [AC_COMPILE_IFELSE([AC_LANG_BOOL_COMPILE_TRY([], [(-1==(-1>>1))])],
 	rb_cv_rshift_sign=yes,
 	rb_cv_rshift_sign=no)])
 if test "$rb_cv_rshift_sign" = yes; then