diff --git a/ChangeLog b/ChangeLog
index 07634e81ba..add968a321 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Dec 11 09:40:21 2007  Tanaka Akira  <akr@fsij.org>
+
+	* include/ruby/oniguruma.h (ONIGENC_CONSTRUCT_MBCLEN_NEEDMORE):
+	  parenthesize an argument.
+
 Tue Dec 11 02:23:32 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* eval.c (rb_method_missing): RDoc update patch from Hugh Sasse
diff --git a/include/ruby/oniguruma.h b/include/ruby/oniguruma.h
index df4d07b115..0cf2e0c6e4 100644
--- a/include/ruby/oniguruma.h
+++ b/include/ruby/oniguruma.h
@@ -285,7 +285,7 @@ ONIG_EXTERN OnigEncodingType OnigEncodingGB18030;
 
 #define ONIGENC_CONSTRUCT_MBCLEN_CHARFOUND(n)   (n)
 #define ONIGENC_CONSTRUCT_MBCLEN_INVALID()      (-1)
-#define ONIGENC_CONSTRUCT_MBCLEN_NEEDMORE(n)    (-1-n)
+#define ONIGENC_CONSTRUCT_MBCLEN_NEEDMORE(n)    (-1-(n))
 
 static inline int onigenc_mbclen_charfound(int r) { return 0 < r ? r : 0; }
 static inline int onigenc_mbclen_needmore(int r) { return r < -1 ? -1 - r : 0; }