diff --git a/sys/net80211/ieee80211_crypto.h b/sys/net80211/ieee80211_crypto.h
--- a/sys/net80211/ieee80211_crypto.h
+++ b/sys/net80211/ieee80211_crypto.h
@@ -273,6 +273,6 @@
 		const struct ieee80211_frame *, const struct ieee80211_key *,
 		uint64_t rsc, int tid);
 void	ieee80211_notify_michael_failure(struct ieee80211vap *,
-		const struct ieee80211_frame *, u_int keyix);
+		const struct ieee80211_frame *, ieee80211_keyix keyix);
 #endif /* defined(__KERNEL__) || defined(_KERNEL) */
 #endif /* _NET80211_IEEE80211_CRYPTO_H_ */
diff --git a/sys/net80211/ieee80211_crypto.c b/sys/net80211/ieee80211_crypto.c
--- a/sys/net80211/ieee80211_crypto.c
+++ b/sys/net80211/ieee80211_crypto.c
@@ -800,7 +800,8 @@
 			 * modules to handle a NULL key and not to dereference
 			 * it.
 			 */
-			ieee80211_notify_michael_failure(vap, wh, -1);
+			ieee80211_notify_michael_failure(vap, wh,
+			    IEEE80211_KEYIX_NONE);
 			return (0);
 		}
 
diff --git a/sys/net80211/ieee80211_freebsd.c b/sys/net80211/ieee80211_freebsd.c
--- a/sys/net80211/ieee80211_freebsd.c
+++ b/sys/net80211/ieee80211_freebsd.c
@@ -870,7 +870,7 @@
 
 void
 ieee80211_notify_michael_failure(struct ieee80211vap *vap,
-	const struct ieee80211_frame *wh, u_int keyix)
+	const struct ieee80211_frame *wh, ieee80211_keyix keyix)
 {
 	struct ifnet *ifp = vap->iv_ifp;