Tesla is making a big change to its network of free fast-charging stations. Any customer who orders a Tesla Model X or Model S after January 1st, 2017, will have to pay “a small fee” when filling up at a Supercharger station. Customers will also have to take delivery of those cars by April 1st, 2017 — so the fees will apply to people who preordered the Model 3. Tesla says the fee will be “less than the price of filling up a comparable gas car.”

Current Tesla owners with Supercharger-equipped cars will be able to use the stations for free for the life of those vehicles, and a Tesla spokesperson tells The Verge that the free charging will transfer to successive owners. Customers who buy Teslas after that January 1st cutoff will be afforded 400 kWh of free Supercharging credits each year, good for about 1,000 miles, according to Tesla. The company says it will release more details about the change later this year, but added that “prices may fluctuate over time and vary regionally based on the cost of electricity.”

“Less than the price of filling up a comparable gas car.”

A change like this was likely to happen eventually, especially as Tesla tries to ramp up production to 500,000 units per year in order to meet the anticipated demand for the Model 3. “Our Supercharger Network will never be a profit center,” the company wrote in a blog post about the change. Tesla says that, by losing less money on providing free electricity at these stations, that the fees will subsidize the continued expansion of the Supercharger network. The Superchargers allow for a full charge in about 75 minutes or a half charge in about 30 — much faster than the standard Level 1 or Level 2 chargers found around the US — and Tesla has built 734 Supercharger stations (with nearly 5,000 chargers) since the network was started in 2012.

Tesla has said in the past that Superchargers were meant to be used more during longer trips, instead of as a daily charging solution. In today’s post, the company continued that line of thinking, saying that it believes the best way for customers to regularly charge their cars is during off-hours at home or work, “just as you would charge your cell phone.”