ClassPass announced Wednesday that it plans to discontinue its unlimited membership plan – and the company’s diehard fans are not happy.

The monthly subscription service for gyms and workout classes announced in a blog post that it’s doing away with the plan that helped the company make its name, citing “a fundamental problem” with the idea of unlimited classes.

CEO Payal Kadakia wrote in the post that ClassPass would be “sabotaging the vision at the very heart of this company” if it encouraged users to continue using Unlimited.

Now, the company is making its 5- and 10-packs of classes – which it introduced earlier this year – the only option for users, migrating its unlimited users over to the 10-class plan, which costs $135 per month.Those members will receive 10 free classes every month for the first three months, the company said.

But several unlimited plan users disagreed with the changes and took to Twitter to voice their frustration with the company’s decision.

https://twitter.com/kdwignall/status/793834549897629696

https://twitter.com/CarnissaSays/status/793834531572686848

https://twitter.com/socallmeshirley/status/793830558417559553

https://twitter.com/WastedWardrobe/status/793829951384322049

https://twitter.com/lindsfrances/status/793830226186870784

https://twitter.com/EzraGrossman2/status/793831579219025920

https://twitter.com/KBheyy/status/793830985909633024

https://twitter.com/stevilou/status/793833452164513792

https://twitter.com/danimop/status/793830112940609536

https://twitter.com/ashnagesh/status/793836135592099841

https://twitter.com/daisyojordan/status/793831864641458176

Kadakia wrote on the company's blog that ClassPass plans to roll out new features in the coming months to "enhance" memberships, and has been sending apologies and working to assuage its disappointed users on the ClassPass Twitter account since announcing the news.

You can read the full post about the changes on the ClassPass blog.