--- a/ibss.c
+++ b/ibss.c
@@ -83,6 +83,20 @@ static int join_ibss(struct nl80211_stat
 		argc--;
 	}
 
+	/* multicast rate */
+	if (argc > 1 && strcmp(argv[0], "mcast-rate") == 0) {
+		argv++;
+		argc--;
+
+		rate = strtod(argv[0], &end);
+		if (*end != '\0')
+			return 1;
+
+		NLA_PUT_U32(msg, NL80211_ATTR_MCAST_RATE, (int) rate * 10);
+		argv++;
+		argc--;
+	}
+
 	if (!argc)
 		return 0;
 
@@ -109,7 +123,7 @@ COMMAND(ibss, leave, NULL,
 	"Leave the current IBSS cell.");
 COMMAND(ibss, join,
 	"<SSID> <freq in MHz> [fixed-freq] [<fixed bssid>] "
-	"[basic-rates <rate in Mbps,rate2,...>] [key d:0:abcde]",
+	"[basic-rates <rate in Mbps,rate2,...>] [mcast-rate <rate in Mbps>] [key d:0:abcde]",
 	NL80211_CMD_JOIN_IBSS, 0, CIB_NETDEV, join_ibss,
 	"Join the IBSS cell with the given SSID, if it doesn't exist create\n"
 	"it on the given frequency. When fixed frequency is requested, don't\n"
