diff --git a/ChangeLog b/ChangeLog
index 72f0592f2c..79e749dddd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Mar 14 19:54:37 2011  Tanaka Akira  <akr@fsij.org>
+
+	* ext/openssl/ossl_x509cert.c: parenthesize macro arguments.
+
 Sun Mar 13 18:11:28 2011  Tanaka Akira  <akr@fsij.org>
 
 	* ext/openssl/ossl_x509attr.c: parenthesize macro arguments.
diff --git a/ext/openssl/ossl_x509cert.c b/ext/openssl/ossl_x509cert.c
index 0217ffc0e1..58640d135f 100644
--- a/ext/openssl/ossl_x509cert.c
+++ b/ext/openssl/ossl_x509cert.c
@@ -11,20 +11,20 @@
 #include "ossl.h"
 
 #define WrapX509(klass, obj, x509) do { \
-    if (!x509) { \
+    if (!(x509)) { \
 	ossl_raise(rb_eRuntimeError, "CERT wasn't initialized!"); \
     } \
-    obj = Data_Wrap_Struct(klass, 0, X509_free, x509); \
+    (obj) = Data_Wrap_Struct((klass), 0, X509_free, (x509)); \
 } while (0)
 #define GetX509(obj, x509) do { \
-    Data_Get_Struct(obj, X509, x509); \
-    if (!x509) { \
+    Data_Get_Struct((obj), X509, (x509)); \
+    if (!(x509)) { \
 	ossl_raise(rb_eRuntimeError, "CERT wasn't initialized!"); \
     } \
 } while (0)
 #define SafeGetX509(obj, x509) do { \
-    OSSL_Check_Kind(obj, cX509Cert); \
-    GetX509(obj, x509); \
+    OSSL_Check_Kind((obj), cX509Cert); \
+    GetX509((obj), (x509)); \
 } while (0)
 
 /*