--- a/iw.h
+++ b/iw.h
@@ -146,7 +146,7 @@ void print_ht_capability(__u16 cap);
 
 const char *iftype_name(enum nl80211_iftype iftype);
 const char *command_name(enum nl80211_commands cmd);
-int ieee80211_channel_to_frequency(int chan);
+int ieee80211_channel_to_frequency(int chan, enum nl80211_band band);
 int ieee80211_frequency_to_channel(int freq);
 
 void print_ssid_escaped(const uint8_t len, const uint8_t *data);
--- a/phy.c
+++ b/phy.c
@@ -66,8 +66,12 @@ static int handle_freqchan(struct nl_msg
 	if (*end)
 		return 1;
 
-	if (chan)
-		freq = ieee80211_channel_to_frequency(freq);
+	if (chan) {
+		enum nl80211_band band;
+		band = freq <= 14 ? NL80211_BAND_2GHZ : NL80211_BAND_5GHZ;
+		freq = ieee80211_channel_to_frequency(freq, band);
+	}
+
 
 	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_FREQ, freq);
 	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_CHANNEL_TYPE, htval);
--- a/util.c
+++ b/util.c
@@ -248,31 +248,37 @@ const char *command_name(enum nl80211_co
 	return cmdbuf;
 }
 
-int ieee80211_channel_to_frequency(int chan)
+int ieee80211_channel_to_frequency(int chan, enum nl80211_band band)
 {
-	if (chan < 14)
-		return 2407 + chan * 5;
-
-	if (chan == 14)
-		return 2484;
-
-	/* FIXME: dot11ChannelStartingFactor (802.11-2007 17.3.8.3.2) */
-	return (chan + 1000) * 5;
+	/* see 802.11-2007 17.3.8.3.2 and Annex J
+	 * there are overlapping channel numbers in 5GHz and 2GHz bands */
+	if (band == NL80211_BAND_5GHZ) {
+		if (chan >= 182 && chan <= 196)
+			return 4000 + chan * 5;
+		else
+			return 5000 + chan * 5;
+	} else { /* NL80211_BAND_2GHZ */
+		if (chan == 14)
+			return 2484;
+		else if (chan < 14)
+			return 2407 + chan * 5;
+		else
+			return 0; /* not supported */
+	}
 }
 
 int ieee80211_frequency_to_channel(int freq)
 {
+	/* see 802.11-2007 17.3.8.3.2 and Annex J */
 	if (freq == 2484)
 		return 14;
-
-	if (freq < 2484)
+	else if (freq < 2484)
 		return (freq - 2407) / 5;
-
-	/* FIXME: dot11ChannelStartingFactor (802.11-2007 17.3.8.3.2) */
-	if (freq < 45000)
-		return freq/5 - 1000;
-
-	if (freq >= 58320 && freq <= 64800)
+	else if (freq >= 4910 && freq <= 4980)
+		return (freq - 4000) / 5;
+	else if (freq < 45000)
+		return (freq - 5000) / 5;
+	else if (freq >= 58320 && freq <= 64800)
 		return (freq - 56160) / 2160;
 
 	return 0;