diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 2f302d3..0b27b14 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -95,6 +95,7 @@
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <asm/uaccess.h>
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>