diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 3a16d4fdaa052817135c885b23cb28d90d872ec6..9336b829cc81e266d78e82c3b6735686371af6be 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -68,6 +68,7 @@
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
 #include <net/sock.h>
+#include <net/cls_cgroup.h>
 
 #include <asm/uaccess.h>
 
diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index a4dc5b027bd9cc7731b7fab1146508896c0b215c..e88527a68454671c88ea9f3d0474ca15b1d726bb 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h
@@ -24,6 +24,8 @@ struct cgroup_cls_state
 	u32 classid;
 };
 
+extern void sock_update_classid(struct sock *sk);
+
 #ifdef CONFIG_NET_CLS_CGROUP
 static inline u32 task_cls_classid(struct task_struct *p)
 {
@@ -62,6 +64,10 @@ static inline u32 task_cls_classid(struct task_struct *p)
 }
 #endif
 #else
+static inline void sock_update_classid(struct sock *sk)
+{
+}
+
 static inline u32 task_cls_classid(struct task_struct *p)
 {
 	return 0;
diff --git a/include/net/sock.h b/include/net/sock.h
index 72132aef53fc61a721ce23c8fbc4fe17cb7a9699..160a68093dbc692d13a4ebd8e23a7a39424a585c 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1486,14 +1486,6 @@ extern void *sock_kmalloc(struct sock *sk, int size,
 extern void sock_kfree_s(struct sock *sk, void *mem, int size);
 extern void sk_send_sigurg(struct sock *sk);
 
-#ifdef CONFIG_CGROUPS
-extern void sock_update_classid(struct sock *sk);
-#else
-static inline void sock_update_classid(struct sock *sk)
-{
-}
-#endif
-
 /*
  * Functions to fill in entries in struct proto_ops when a protocol
  * does not implement a particular function.