Spencer Pratt and Heidi Montag, a pestering present on MTV’s The Hills, have been tapped to play themselves on an episode of the CBS sitcom How I Met My Mother, scheduled to air in January 2009.

“We can confirm that Heidi and Spencer will appear on the show, but we can’t give away anything specific about the episode. All we can say is that they play themselves, and one of them is ‘The Mother,’” says co-creator and executive producer Craig Thomas.

In the episode, Marshall (Jason Segel) is searching for a place to “read a magazine” while at the office, when Heidi and Spencer tease him from the cover of his copy of Them Weekly.

Heidi and Spencer will film their guest spot on How I Met Your Mother this week.