diff --git a/fs/9p/fid.c b/fs/9p/fid.c
index 08b2eb1..82ee460 100644
--- a/fs/9p/fid.c
+++ b/fs/9p/fid.c
@@ -24,6 +24,7 @@
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
+#include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/idr.h>
 #include <net/9p/9p.h>