diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index b382c7c..e526a8c 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1857,6 +1857,7 @@
 	WLAN_KEY_LEN_CCMP = 16,
 	WLAN_KEY_LEN_TKIP = 32,
 	WLAN_KEY_LEN_AES_CMAC = 16,
+	WLAN_KEY_LEN_SMS4 = 32,
 };
 
 #define IEEE80211_WEP_IV_LEN		4