diff --git a/sys/net80211/ieee80211_scan_sta.c b/sys/net80211/ieee80211_scan_sta.c
--- a/sys/net80211/ieee80211_scan_sta.c
+++ b/sys/net80211/ieee80211_scan_sta.c
@@ -271,6 +271,14 @@
 	LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
 found:
 	ise = &se->base;
+	if (se->se_seen && ise->se_chan->ic_ieee != curchan->ic_ieee) {
+		/* Where do we filter wrong ones out based on DSPARAMS/HTINFO? */
+		net80211_vap_printf(vap, "BSSID %6D already seen during this "
+		   "scan on chan %d (se_rssi: %d), now chan %d (rssi: %d)\n",
+		   macaddr, ":",
+		   ise->se_chan->ic_ieee, (ise->se_rssi / 2) + ise->se_noise,
+		   curchan->ic_ieee, (rssi / 2) + noise);
+	}
 	/* XXX ap beaconing multiple ssid w/ same bssid */
 	if (sp->ssid[1] != 0 &&
 	    (ISPROBE(subtype) || ise->se_ssid[1] == 0))