diff --git a/ChangeLog b/ChangeLog
index 3f2bb5eb73..d280a33a05 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Mar 29 05:19:57 2011  Tanaka Akira  <akr@fsij.org>
+
+	* ext/socket/raddrinfo.c: parenthesize macro arguments.
+
 Tue Mar 29 00:03:51 2011 Tajima Akil <artonx@yahoo.co.jp>	
 
 	* test/webrick/test_filehandler.rb (test_short_filename):
diff --git a/ext/socket/raddrinfo.c b/ext/socket/raddrinfo.c
index 6d2a5e9171..8cd25f0e07 100644
--- a/ext/socket/raddrinfo.c
+++ b/ext/socket/raddrinfo.c
@@ -545,7 +545,7 @@ addrinfo_s_allocate(VALUE klass)
     return TypedData_Wrap_Struct(klass, &addrinfo_type, 0);
 }
 
-#define IS_ADDRINFO(obj) rb_typeddata_is_kind_of(obj, &addrinfo_type)
+#define IS_ADDRINFO(obj) rb_typeddata_is_kind_of((obj), &addrinfo_type)
 static inline rb_addrinfo_t *
 check_addrinfo(VALUE self)
 {