Tesla will begin charging owners who leave their cars at Supercharger stations after they have completed charging, the company announced today. The new fee is an attempt to increase turnover at the charging stations, which have become increasingly congested as more Teslas are sold.

After charging is complete, Tesla owners will have five minutes to disconnect and move their cars, or they will be charged $0.40 per minute for as long as the car remains hooked up to the Supercharger. Tesla CEO Elon Musk originally hinted at the company taking action on Twitter last weekend.

@loic You're right, this is becoming an issue. Supercharger spots are meant for charging, not parking. Will take action. — Elon Musk (@elonmusk) December 11, 2016

Tesla owners have in the past complained about fellow owners leaving cars in Supercharger spots for hours. The Tesla blog post notes that no one would ever leave their car parked at a gas pump for that length of time and that Supercharger users should be similarly courteous.

The company says the fee will go into effect immediately, and that it “is purely about increasing customer happiness and we hope to never make any money from it.” Owners will need to set up an account on Tesla’s website to pay any fees incurred.

Update: Musk clarified on Twitter that this will be relative and will only take effect if charging bays are crowded: