diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 4054399..0d00ac9 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -449,7 +449,8 @@
 	/* APs need special treatment */
 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
 		struct ieee80211_sub_if_data *vlan, *tmpsdata;
-		struct beacon_data *old_beacon = sdata->u.ap.beacon;
+		struct beacon_data *old_beacon =
+			rtnl_dereference(sdata->u.ap.beacon);
 
 		/* sdata_running will return false, so this will disable */
 		ieee80211_bss_info_change_notify(sdata,