diff --git a/ChangeLog b/ChangeLog
index 025569331c..85dbe684d0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Apr 12 08:56:44 2015  Tanaka Akira  <akr@fsij.org>
+
+	* ext/-test-/file/fs.c: OpenBSD needs sys/param.h before sys/mount.h.
+
 Sun Apr 12 08:52:01 2015  Tanaka Akira  <akr@fsij.org>
 
 	* test/ruby/test_file_exhaustive.rb: Test suid, sgid and sticky file.
diff --git a/ext/-test-/file/fs.c b/ext/-test-/file/fs.c
index 1ab067e1b2..f0be84ad3b 100644
--- a/ext/-test-/file/fs.c
+++ b/ext/-test-/file/fs.c
@@ -1,6 +1,9 @@
 #include "ruby/ruby.h"
 #include "ruby/io.h"
 
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
 #ifdef HAVE_SYS_MOUNT_H
 #include <sys/mount.h>
 #endif