diff --git a/fs/buffer.c b/fs/buffer.c
index 1c62203..6cbfcea 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -40,6 +40,7 @@
 #include <linux/cpu.h>
 #include <linux/bitops.h>
 #include <linux/mpage.h>
+#include <linux/bit_spinlock.h>
 
 static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
 static void invalidate_bh_lrus(void);