diff --git a/sys/bus/u4b/wlan/if_mtw.c b/sys/bus/u4b/wlan/if_mtw.c
--- a/sys/bus/u4b/wlan/if_mtw.c
+++ b/sys/bus/u4b/wlan/if_mtw.c
@@ -3696,8 +3696,11 @@
 	uint8_t bbp, rf, txpow1;
 	int i;
 	/* find the settings for this channel */
-	for (i = 0; mt7601_rf_chan[i].chan != chan; i++)
-		;
+	for (i = 0; i < nitems(mt7601_rf_chan); i++)
+		if (mt7601_rf_chan[i].chan == chan)
+			break;
+	if (i == nitems(mt7601_rf_chan))
+		return;
 
 	mtw_rf_write(sc, 0, 17, mt7601_rf_chan[i].r17);
 	mtw_rf_write(sc, 0, 18, mt7601_rf_chan[i].r18);