diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 5ac8902..ee82d4e 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -26,6 +26,7 @@
 
 #include <crypto/hash.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <net/ip.h>
 #include <net/ah.h>
 #include <linux/crypto.h>