Walmart (WMT) announced that it will require all customers to wear face masks at all of its stores starting July 20. The face mask requirement will also be required at Sam’s Club warehouse stores.

“To help bring consistency across stores and clubs, we will require all shoppers to wear a face covering starting Monday, July 20. This will give us time to inform customers and members of the changes, post signage and train associates on the new protocols," Dacona Smith, chief operating officer at Walmart U.S., and Lance de la Rosa, chief operating officer at Sam’s Club, said in a statement.

Currently, 65% of Walmart’s more than 5,000 stores and clubs are located in areas where there is a government mandate to wear a face mask.

Walmart will enforce the face mask requirement with a health ambassador that will be stationed at store entrances to remind customers of the new policy. Health ambassadors will wear a black polo shirt instead of the traditional blue vest and will help customers that do not have a mask when arriving at a Walmart store find a “solution.”

Complimentary masks will be provided at Sam’s Club for members that do not have one, or they can be purchased at stores.

Walmart will also limit access to its stores through one entrance to help monitor the face mask requirement.

Walmart joins several other retailers that have enacted a face mask policy at their stores. One of the first retailers to introduce the requirement was Costco. Menards, Starbucks, and more recently, Best Buy have also implemented face mask policies.

Shares of Walmart were trading at $133.58 as of 11:02 a.m. ET, up $1.61 or 1.22%.

Walmart signage is displayed outside a company's store in Chicago, Illinois, Nov. 23, 2016. REUTERS/Kamil Krzaczynski