Heidi Montag and Spencer Pratt
04/17/2009 at 04:55 PM EDT
will soon be Mrs. Spencer Pratt.
stars, who reportedly eloped
in November 2008, plan to tie the knot in California on April 25, PEOPLE confirms.
According to a source, Montag, 22, and Pratt, 25, will make it official in a sunset ceremony at the Westminster Presbyterian Church in Pasadena, Calif., on Saturday.
The upcoming wedding comes five months after the pair flew to Mexico for what Pratt described as a "totally spur of the moment" ceremony
. Their Mexican celebration included "margaritas, sunsets and beautiful settings" but no friends or family.
A rep for the couple could not be reached for comment.