diff --git a/packet.c b/packet.c
index e7abb3416..4cce4133a 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.291 2020/03/06 18:20:44 markus Exp $ */
+/* $OpenBSD: packet.c,v 1.292 2020/06/24 15:10:38 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -282,7 +282,8 @@ ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
 int
 ssh_packet_is_rekeying(struct ssh *ssh)
 {
-	return ssh->state->rekeying || ssh->kex->done == 0;
+	return ssh->state->rekeying ||
+	    (ssh->kex != NULL && ssh->kex->done == 0);
 }
 
 /*
@@ -345,6 +346,8 @@ ssh_packet_set_mux(struct ssh *ssh)
 {
 	ssh->state->mux = 1;
 	ssh->state->rekeying = 0;
+	kex_free(ssh->kex);
+	ssh->kex = NULL;
 }
 
 int