Anderson, who played Scully on the popular science fiction series for nearly a decade on television, said it took her a little while to get back into character when she was asked to reprise the role for the big screen, the New York Daily News reported Saturday.
"I found it quite tricky over the first couple of days to slide back into it," Anderson said. "It was kind of unexpected and a bit freakish for me."
Yet Anderson said after her first scene with actor David Duchovny, who played Agent Fox Mulder on "The X-Files" series, it got easier.
"It was definitely the moment that (we) got into the same room together that it felt familiar again," Anderson told the Daily News.
The newspaper said it has been 10 years since Anderson and Duchovny assumed the roles after starring in 1998's "The X-Files: Fight the Future."