diff --git a/fs/hpfs/inode.c b/fs/hpfs/inode.c
index 39a1bfb..fe703ae 100644
--- a/fs/hpfs/inode.c
+++ b/fs/hpfs/inode.c
@@ -6,6 +6,7 @@
  *  inode VFS functions
  */
 
+#include <linux/smp_lock.h>
 #include "hpfs_fn.h"
 
 void hpfs_init_inode(struct inode *i)