diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0af2e38..8a6518a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -26,6 +26,7 @@
 #include <linux/completion.h>
 #include <linux/backing-dev.h>
 #include <linux/wait.h>
+#include <linux/slab.h>
 #include <asm/kmap_types.h>
 #include "extent_io.h"
 #include "extent_map.h"