diff --git a/ChangeLog b/ChangeLog
index e0f690d2bc..fd9af09663 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Mar 10 03:00:43 2011  Tanaka Akira  <akr@fsij.org>
+
+	* ext/openssl/ossl_ssl.c: parenthesize macro arguments.
+
 Wed Mar  9 23:51:26 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
 
 	* test/ruby/test_io_m17n.rb (test_io_new_enc): "sjis" is now an alias
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index e26be8a365..e5cce0f0e8 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -16,12 +16,12 @@
 #  include <unistd.h> /* for read(), and write() */
 #endif
 
-#define numberof(ary) (int)(sizeof(ary)/sizeof(ary[0]))
+#define numberof(ary) (int)(sizeof(ary)/sizeof((ary)[0]))
 
 #ifdef _WIN32
 #  define TO_SOCKET(s) _get_osfhandle(s)
 #else
-#  define TO_SOCKET(s) s
+#  define TO_SOCKET(s) (s)
 #endif
 
 VALUE mSSL;
@@ -1064,9 +1064,9 @@ ossl_ssl_setup(VALUE self)
 }
 
 #ifdef _WIN32
-#define ssl_get_error(ssl, ret) (errno = rb_w32_map_errno(WSAGetLastError()), SSL_get_error(ssl, ret))
+#define ssl_get_error(ssl, ret) (errno = rb_w32_map_errno(WSAGetLastError()), SSL_get_error((ssl), (ret)))
 #else
-#define ssl_get_error(ssl, ret) SSL_get_error(ssl, ret)
+#define ssl_get_error(ssl, ret) SSL_get_error((ssl), (ret))
 #endif
 
 static void