diff --git a/ChangeLog b/ChangeLog
index 19e674a42a..63813269e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul  7 06:56:15 2011  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* cont.c (FIBER_STACK_FLAGS): workaround fix for r32420 on FreeBSD.
+
 Thu Jul  7 06:46:12 2011  Eric Hodel  <drbrain@segment7.net>
 
 	* benchmark/driver.rb:  Add difference column to report that averages
diff --git a/cont.c b/cont.c
index adf975ba7d..37c301a89d 100644
--- a/cont.c
+++ b/cont.c
@@ -517,7 +517,7 @@ fiber_entry(void *arg)
 }
 #else /* _WIN32 */
 
-#ifdef MAP_STACK
+#if defined(MAP_STACK) && !defined(__FreeBSD__)
 #define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON | MAP_STACK)
 #else
 #define FIBER_STACK_FLAGS (MAP_PRIVATE | MAP_ANON)