diff --git a/plugins/phonesim.c b/plugins/phonesim.c
index 6c3c1e8d..2c028c0f 100644
--- a/plugins/phonesim.c
+++ b/plugins/phonesim.c
@@ -248,9 +248,14 @@ static int phonesim_enable(struct ofono_modem *modem)
 	}
 
 	if (data->use_mux) {
+		g_at_chat_send(data->chat, "ATE0", NULL, NULL, NULL, NULL);
+
 		g_at_mux_setup_gsm0710(data->chat, mux_setup, modem, NULL);
+
 		g_at_chat_unref(data->chat);
 		data->chat = NULL;
+
+		return -EINPROGRESS;
 	}
 
 	g_at_chat_send(data->chat, "AT+CSCS=\"GSM\"", none_prefix,