Driving instructors are being warned that if they have a sexual relationship with a young student it will now be seen as "exploitation".
The Driver and Vehicle Standards Agency (DVSA) says if instructors become sexually involved with 16 and 17-year-old pupils, even if it's consensual, they could face being punished.
In 2016-17 there were 109 investigations into instructor misconduct, which includes inappropriate sexual behaviour.
Instructors could be removed from the approved register if they're found to be "a high risk".
Last year, Newsbeat spoke to one learner driver who had a bad experience with her driving instructor.
"I started noticing little comments. He'd talk about whether I cycled anywhere and said 'You'd look good in Lycra'.
"He added me on Facebook and would ask me questions about whether I was single. As soon as I ended the lessons, I had a text from him asking me out for a drink."
Jess (not her real name) says this left her "mortified" as she thought she was way too young for him.
The changes were brought in after MP Richard Graham asked the Prime Minister Theresa May to look into the issue.
He said the law should be changed to protect young drivers from "being groomed by a predatory instructor" and that instructors should be "covered by the same rules as teachers".
In 2001, the law was changed to make it illegal for teachers to engage in sexual activity with pupils at their school, if they were aged under 18.
The DVSA says it will investigate serious allegations of improper behaviour and refer its findings to the police.
It told Newsbeat that could include instructors using sexualised language, unnecessary physical or inappropriate contact and sending indecent messages or images to their pupils.
"We take the safety of learner drivers extremely seriously and will thoroughly investigate any complaints about the conduct of instructors and will involve the police where necessary," Andy Rice, DVSA Head of Counter-Fraud and Investigations, said.
"Any driving instructors threatening the safety of learner drivers and failing to meet the 'fit and proper' criteria will be removed from the ADI register."
At the moment, all driving instructors are subject to enhanced criminal record checks which must be renewed every four years.
The DVSA says the best way of finding a fully-qualified instructor is to go to www.gov.uk/drivinglessons.
You can also check out the full driving instructor code of practice.