California lawmakers said Monday they have started drafting legislation that would close a loophole in a century-old rape law that fails to protect unmarried women.

The 19th century mandate makes it a crime for a man to have sex with a woman by tricking her into thinking he is her husband. What the law fails to address is if that woman is unmarried.

Assembly Speaker John Perez told FoxNews.com he would prioritize the change in the rape code in the 2013 legislative session, but he did not give a timeline.

The loophole in the law was used by a state appeals court last week to overturn the rape conviction of a Los Angeles County man who had sex with a woman while pretending to be her boyfriend. The woman, who was in a dark bedroom, resisted only after she realized the man was not her boyfriend. Charges were filed against the man and he was convicted, but a Los Angeles-based appeals court overturned the ruling, citing the archaic language.

Last year, Central Coast Assemblyman Katcho Achadjian led a push to update the law. The measure made it through a committee but was defeated on the Senate floor. Achadjian said he will introduce a similar bill to expand the definition of rape to include impersonating the victim’s boyfriend, fiance or significant other.

“We are back in session and we are working on the language as we speak,” Perez said. “We passed it once, and we will pass it again.”

This isn’t the first time lawmakers in California have had to answer for this lapse. Thirty years ago a similar case was tried and overturned. At that time, the court warned the state to make changes. In the three decades that have passed, the attempts that were made have gained very little traction – but that could be changing.

California Coalition Against Sexual Assault Director Denice Labertew says a half a dozen lawmakers have been in contact with her organization following last week’s ruling.

“The challenge is that when we are creating changes in the law we need to be thoughtful of unintended consequences,” Labertew said. “I have received calls and emails from lawmakers looking to make meaningful changes.”

Patty Bellasalma, president of the California National Organization for Women, said it's incumbent upon legislators to ensure laws mesh with modern-day lifestyles.

"If unmarried women aren't included, that means the intent of the law is not about protecting women, it's about protecting something else," she said.