diff --git a/fs/ceph/auth_x.c b/fs/ceph/auth_x.c
index 8d8a849..d9001a4 100644
--- a/fs/ceph/auth_x.c
+++ b/fs/ceph/auth_x.c
@@ -4,6 +4,7 @@
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/random.h>
+#include <linux/slab.h>
 
 #include "auth_x.h"
 #include "auth_x_protocol.h"