The Australian actor, who recently filmed a love scene for new drama House of Lies alongside television presenter Cat Deeley, said that he found it "hilarious" when his package needed enhancing on set.
Lawson told the Herald Sun: "My manhood was not enough, it didn't read on camera, so I had to shove a piece... I'm trying to be... Oh you know what, we're adults... [a prosthetic] down my pants and it was hilarious, no doubt about it."
When asked if he was required to get approval for the enhancement, he joked: "There was a boardroom meeting where I had to parade, America's Next Top Model style, in front of them with [it]."
Lawson is currently dating Charlie's Angels actress Rachael Taylor. Months before getting together with Lawson, Taylor was attacked by then-boyfriend and Underbelly star Matthew Newton, and she has said that Lawson has helped her feel "better".
Taylor said of him: "My Josh. Josh has been a really great influence on me and I adore him. We are really happy. We have a deep friendship, a deep respect."
> 'Charlie's Angels' actress Rachael Taylor "sensitive" about fight scenes
House of Lies airs on Sundays at 10/9c on Showtime.
Watch the trailer for House of Lies below: