diff --git a/ChangeLog b/ChangeLog
index 63f7edc464..c46c2c4235 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Oct 21 12:10:20 2011  Naohisa Goto  <ngotogenome@gmail.com>
+
+	* atomic.h: change Solaris checking macro because atomic_ops can work
+	  not only with Sun Studio but also with Fujitsu C Compiler.
+
 Fri Oct 21 02:11:00 2011  Martin Bosslet  <Martin.Bosslet@googlemail.com>
 
 	* ext/openssl/ossl_ns_spki.c: Complete documentation.
diff --git a/atomic.h b/atomic.h
index 33f731927d..6dbad6db2d 100644
--- a/atomic.h
+++ b/atomic.h
@@ -42,7 +42,7 @@ typedef unsigned int rb_atomic_t; /* Anything OK */
 # define ATOMIC_OR(var, val) __sync_or_and_fetch(&(var), (val))
 # define ATOMIC_EXCHANGE(var, val) __sync_lock_test_and_set(&(var), (val))
 
-#elif defined(__SUNPRO_C)
+#elif defined(__sun) || defined(__sun__)
 #include <atomic.h>
 typedef unsigned int rb_atomic_t;