diff --git a/mqtt_client.c b/mqtt_client.c
index f45c43b..22490eb 100644
--- a/mqtt_client.c
+++ b/mqtt_client.c
@@ -309,6 +309,7 @@ static esp_err_t esp_mqtt_connect(esp_mqtt_client_handle_t client, int timeout_m
         ESP_LOGE(TAG, "Invalid MSG_TYPE response: %d, read_len: %d", mqtt_get_type(client->mqtt_state.in_buffer), read_len);
         return ESP_FAIL;
     }
+    client->mqtt_state.in_buffer_read_len = 0;
     connect_rsp_code = mqtt_get_connect_return_code(client->mqtt_state.in_buffer);
     switch (connect_rsp_code) {
     case CONNECTION_ACCEPTED:
@@ -1192,6 +1193,7 @@ int esp_mqtt_client_subscribe(esp_mqtt_client_handle_t client, const char *topic
     client->mqtt_state.pending_msg_type = mqtt_get_type(client->mqtt_state.outbound_message->data);
     client->mqtt_state.pending_msg_count ++;
     mqtt_enqueue(client); //move pending msg to outbox (if have)
+    outbox_set_pending(client->outbox, client->mqtt_state.pending_msg_id, TRANSMITTED);
 
     if (mqtt_write_data(client) != ESP_OK) {
         ESP_LOGE(TAG, "Error to subscribe topic=%s, qos=%d", topic, qos);
@@ -1220,6 +1222,7 @@ int esp_mqtt_client_unsubscribe(esp_mqtt_client_handle_t client, const char *top
     client->mqtt_state.pending_msg_type = mqtt_get_type(client->mqtt_state.outbound_message->data);
     client->mqtt_state.pending_msg_count ++;
     mqtt_enqueue(client);
+    outbox_set_pending(client->outbox, client->mqtt_state.pending_msg_id, TRANSMITTED);
 
     if (mqtt_write_data(client) != ESP_OK) {
         ESP_LOGE(TAG, "Error to unsubscribe topic=%s", topic);