diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index bf5cf69c820a..da564efe4f5b 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -44,7 +44,7 @@ struct phonet_net {
 	struct phonet_routes routes;
 };
 
-int phonet_net_id __read_mostly;
+static int phonet_net_id __read_mostly;
 
 static struct phonet_net *phonet_pernet(struct net *net)
 {