Last month, the National Air and Space banned the use of selfie sticks.  The ban became an official Smithsonian policy Tuesday. (Photo by Andrew Harnik for The Washington Post)

The Smithsonian has made it official: Selfie sticks are a no-no.

Last month, several Smithsonian affiliates banned the poles used by visitors to take pictures of themselves. The sticks present a safety hazard, officials said. As of Tuesday, they are not not permitted in any of the Smithsonian’s museums.

According to the Smithsonian Web site, selfie sticks are now included in the policy that prohibits use of tripods and monopods. “This is a preventive measure to protect visitors and objects, especially during crowded conditions,” according to the Web site.

Other museums in the District – including the National Gallery of Art and the Phillips Collection – have banned the selfie stick, as have major museums in Boston, New York and Los Angeles.

The Smithsonian doesn’t want to dampen visitor fun, though. Selfies are encouraged — just without the sticks.

“We encourage museum visitors to take selfies and share their experiences,” the announcement states.