diff --git a/tmate-ssh-client.c b/tmate-ssh-client.c
index 691a49ce..cd3a71b0 100644
--- a/tmate-ssh-client.c
+++ b/tmate-ssh-client.c
@@ -49,6 +49,9 @@ static void on_encoder_write(void *userdata, struct evbuffer *buffer)
 	ssize_t len, written;
 	unsigned char *buf;
 
+	if (!client->channel)
+		return;
+
 	for(;;) {
 		len = evbuffer_get_length(buffer);
 		if (!len)