French companies caught discriminating against women over pay will be given three years to close the gap or face fines under new labour proposals.
The government revealed the planned crackdown to unions and employers on Wednesday, giving them a month to iron out details.
If passed by parliament, the measure will be rolled out by 2020.
Men are still paid on average 9% more than women in France despite equal pay laws going back 45 years.
The measure is part of a social reform bill due to be presented to Prime Minister Edouard Philippe's cabinet at the end of next month.
"The crazy thing is that it all exists in law but equality is missing in practice," said Mr Philippe.
"Our aim is to pass from fine words to true, genuine equality."
How would the new measure work?
Special software would be installed on company payroll systems to monitor unjustified pay gaps.
Larger firms - those employing at least 250 staff - would get the new software next year while firms employing between 50 and 249 staff would be affected from 2020.
The new system would be launched in 2022 and there would be four times the current number of spot checks.
Those firms which failed to address unfair pay gaps within three years of a warning could be fined up to 1% of their wage bill.
How do other countries compare?
Across the 28 EU member states, the average "unexplained" gender pay gap is a little higher than France's at 11.5%, according to Eurostat figures.
Neighbouring Belgium has a gap of just 2.5% whereas for women in Lithuania, it is a staggering 24.2%.