diff --git a/sys/fs/tmpfs/tmpfs_fifoops.c b/sys/fs/tmpfs/tmpfs_fifoops.c
index a2bfa5fce51..eb206ff6906 100644
--- a/sys/fs/tmpfs/tmpfs_fifoops.c
+++ b/sys/fs/tmpfs/tmpfs_fifoops.c
@@ -39,6 +39,7 @@
  __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/mount.h>
 #include <sys/proc.h>
 #include <sys/vnode.h>