diff --git a/src/ap/acs.c b/src/ap/acs.c
index 7da95d6c2..28b0ba71c 100644
--- a/src/ap/acs.c
+++ b/src/ap/acs.c
@@ -963,7 +963,7 @@ acs_find_ideal_chan_mode(struct hostapd_iface *iface,
 		 * crowded primary channel if one was found in the segment */
 		if (iface->current_mode &&
 		    iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A &&
-		    chan != best) {
+		    best && chan != best) {
 			wpa_printf(MSG_DEBUG,
 				   "ACS: promoting channel %d over %d (less interference %Lg/%Lg)",
 				   best->chan, chan->chan,