diff --git a/pipewire-jack/src/pipewire-jack.c b/pipewire-jack/src/pipewire-jack.c
index 60406454c..db2c9381e 100644
--- a/pipewire-jack/src/pipewire-jack.c
+++ b/pipewire-jack/src/pipewire-jack.c
@@ -566,7 +566,15 @@ do_mix_set_io(struct spa_loop *loop, bool async, uint32_t seq,
 		const void *data, size_t size, void *user_data)
 {
 	const struct io_info *info = data;
+	struct port *port = info->mix->port;
 	info->mix->io = info->data;
+	if (info->mix->io) {
+		if (port->n_mix++ == 0 && port->global_mix != NULL)
+			port->global_mix->io = &port->io;
+	} else {
+		if (--port->n_mix == 0 && port->global_mix != NULL)
+			port->global_mix->io = NULL;
+	}
 	return 0;
 }
 
@@ -587,10 +595,11 @@ static void init_mix(struct mix *mix, uint32_t mix_id, struct port *port, uint32
 	mix->io = NULL;
 	mix->n_buffers = 0;
 	spa_list_init(&mix->queue);
-	if (mix_id == SPA_ID_INVALID)
+	if (mix_id == SPA_ID_INVALID) {
 		port->global_mix = mix;
-	else if (port->n_mix++ == 0 && port->global_mix != NULL)
-		mix_set_io(port->global_mix, &port->io);
+		if (port->n_mix > 0)
+			mix_set_io(port->global_mix, &port->io);
+	}
 }
 static struct mix *find_mix_peer(struct client *c, uint32_t peer_id)
 {
@@ -677,8 +686,6 @@ static void free_mix(struct client *c, struct mix *mix)
 	spa_list_remove(&mix->port_link);
 	if (mix->id == SPA_ID_INVALID)
 		port->global_mix = NULL;
-	else if (--port->n_mix == 0 && port->global_mix != NULL)
-		mix_set_io(port->global_mix, NULL);
 	spa_list_remove(&mix->link);
 	spa_list_append(&c->free_mix, &mix->link);
 }