diff --git a/sys/net80211/ieee80211_crypto_tkip.c b/sys/net80211/ieee80211_crypto_tkip.c
index f949255b9c68..6e1fda1fc9d2 100644
--- a/sys/net80211/ieee80211_crypto_tkip.c
+++ b/sys/net80211/ieee80211_crypto_tkip.c
@@ -144,6 +144,7 @@ tkip_setkey(struct ieee80211_key *k)
 		return 0;
 	}
 	k->wk_keytsc = 1;		/* TSC starts at 1 */
+	ctx->rx_phase1_done = 0;
 	return 1;
 }