Amazon has begun hiring seasonal delivery drivers as it beefs up its own internal shipping service to meet the high volume of package deliveries during the busy holiday season.

The ecommerce giant began posting ads for delivery jobs. One job posting in Michigan lists an hourly wage of $16.25 an hour, while another in Ohio has a base pay of $17.25 an hour. Both jobs involve shifts as long as 12 hours. Last month, Amazon raised its minimum wage to $15 an hour in the U.S. and the U.K., following pressure from some members of Congress.

Earlier this year, reports emerged that Amazon was looking into creating its own delivery service, called “Shipping by Amazon,” which would compete directly against UPS and FedEx. In September, the company ordered 20,000 Mercedes-Benz Sprinter vans to help build up a delivery fleet.

It’s not clear what plans Amazon has for its internal delivery service after the holidays and whether the seasonal drivers will have opportunities to remain with Amazon next year. Amazon, which has not commented in detail about its delivery plans, did not respond to a request for comment.

A report by Business Insider said Monday that Amazon would be managing drivers directly and provide them delivery vehicles, a break from its recent practice of relying on a network of delivery partners to handle the last mile of its package deliveries.

Amazon recently warned that its expectations for sales this holiday season could come in below Wall Street forecasts. To help revive demand for its holiday shipments, Amazon said Monday it would offer free shipping for all shoppers this holiday season. Normally, shoppers who aren’t Amazon Prime members need to spend $25 or more to qualify for free shipping.

Amazon’s stock closed down $37.73, or 2.3%, at $1,627.80 on Monday.