diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c
index 3959e0c..3b3813c 100644
--- a/net/ipv4/tunnel4.c
+++ b/net/ipv4/tunnel4.c
@@ -8,6 +8,7 @@
 #include <linux/mutex.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
+#include <linux/slab.h>
 #include <net/icmp.h>
 #include <net/ip.h>
 #include <net/protocol.h>