diff --git a/include/mntopts.h b/include/mntopts.h
index 707bb8c27ff6..d9c91a43b080 100644
--- a/include/mntopts.h
+++ b/include/mntopts.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: mntopts.h,v 1.15 2012/10/19 17:09:06 drochner Exp $	*/
+/*	$NetBSD: mntopts.h,v 1.16 2016/01/22 22:26:45 dholland Exp $	*/
 
 /*-
  * Copyright (c) 1994
@@ -33,6 +33,8 @@
 #ifndef _MNTOPTS_H_
 #define _MNTOPTS_H_
 
+#include <sys/cdefs.h>
+
 struct mntopt {
 	const char *m_option;	/* option name */
 	int m_inverse;		/* if a negative option, eg "dev" */