Use the same macro (_SYS_QUEUE_H) as <sys/queue.h> for header protection This prevents collisions.
diff --git a/include/bsd/queue.h b/include/bsd/queue.h
index e31b26c..407f08b 100644
--- a/include/bsd/queue.h
+++ b/include/bsd/queue.h
@@ -30,8 +30,8 @@
* $FreeBSD: src/sys/sys/queue.h,v 1.58 2004/04/07 04:19:49 imp Exp $
*/
-#ifndef _SYS_QUEUE_H_
-#define _SYS_QUEUE_H_
+#ifndef _SYS_QUEUE_H
+#define _SYS_QUEUE_H
#include <sys/cdefs.h>
@@ -550,4 +550,4 @@ void remque(void *a);
#endif /* _KERNEL */
-#endif /* !_SYS_QUEUE_H_ */
+#endif /* !_SYS_QUEUE_H */