diff --git a/sys/dev/bwn/if_bwn.c b/sys/dev/bwn/if_bwn.c
index 615a3ad57c5f..d13002497457 100644
--- a/sys/dev/bwn/if_bwn.c
+++ b/sys/dev/bwn/if_bwn.c
@@ -1498,7 +1498,7 @@ bwn_setup_channels(struct bwn_mac *mac, int have_bg, int have_a)
 {
 	struct bwn_softc *sc = mac->mac_sc;
 	struct ieee80211com *ic = &sc->sc_ic;
-	uint8_t bands[howmany(IEEE80211_MODE_MAX, 8)];
+	uint8_t bands[IEEE80211_MODE_BYTES];
 
 	memset(ic->ic_channels, 0, sizeof(ic->ic_channels));
 	ic->ic_nchans = 0;
diff --git a/sys/dev/wi/if_wi.c b/sys/dev/wi/if_wi.c
index bccad99af06a..e310257a2fd2 100644
--- a/sys/dev/wi/if_wi.c
+++ b/sys/dev/wi/if_wi.c
@@ -691,7 +691,7 @@ wi_getradiocaps(struct ieee80211com *ic,
     int maxchans, int *nchans, struct ieee80211_channel chans[])
 {
 	struct wi_softc *sc = ic->ic_softc;
-	u_int8_t bands[IEEE80211_MODE_MAX];
+	u_int8_t bands[IEEE80211_MODE_BYTES];
 	int i;
 
 	memset(bands, 0, sizeof(bands));