diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7a4e4bf..cf8d721 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2031,6 +2031,8 @@
 		auth_alg = WLAN_AUTH_OPEN;
 		break;
 	case NL80211_AUTHTYPE_SHARED_KEY:
+		if (IS_ERR(sdata->local->wep_tx_tfm))
+			return -EOPNOTSUPP;
 		auth_alg = WLAN_AUTH_SHARED_KEY;
 		break;
 	case NL80211_AUTHTYPE_FT: