diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 95e646641184..32dcb6085ebe 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -126,16 +126,19 @@ struct net {
 /* Init's network namespace */
 extern struct net init_net;
 
-#ifdef CONFIG_NET
+#ifdef CONFIG_NET_NS
 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
 
-#else /* CONFIG_NET */
-static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
+#else /* CONFIG_NET_NS */
+#include <linux/sched.h>
+#include <linux/nsproxy.h>
+static inline struct net *copy_net_ns(unsigned long flags, struct net *old_net)
 {
-	/* There is nothing to copy so this is a noop */
-	return net_ns;
+	if (flags & CLONE_NEWNET)
+		return ERR_PTR(-EINVAL);
+	return old_net;
 }
-#endif /* CONFIG_NET */
+#endif /* CONFIG_NET_NS */
 
 
 extern struct list_head net_namespace_list;
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 42f1e1c7514f..2c1c59091685 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -347,13 +347,6 @@ struct net *get_net_ns_by_fd(int fd)
 }
 
 #else
-struct net *copy_net_ns(unsigned long flags, struct net *old_net)
-{
-	if (flags & CLONE_NEWNET)
-		return ERR_PTR(-EINVAL);
-	return old_net;
-}
-
 struct net *get_net_ns_by_fd(int fd)
 {
 	return ERR_PTR(-EINVAL);