Citing the “limits of [its] core finances,” Firefox maker Mozilla this week laid off 70 employees. And more layoffs could be on the way.

“Mozilla must do two things in this era: Continue to excel at our current work, while we innovate in the areas most likely to impact the state of the internet and internet life,” Mozilla chairwoman and interim CEO Mitchell Baker writes in a post to the firm’s corporate blog. “In order to do that responsibly, we’ve also had to make some difficult choices which led to the elimination of roles at Mozilla which we announced internally today … to responsibly make additional investments in innovation to improve the internet, we can and must work within the limits of our core finances.”

In that internal memo, which was obtained by TechCrunch, Baker says that a slow rollout of new revenue-generating products explains the layoffs. And that the final number of layoffs may be higher, as the company looks more closely at its international locations as well.

“We expected to be earning revenue in 2019 and 2020 from new subscription products as well as higher revenue from sources outside of search,” the memo explains. “This did not happen. Our 2019 plan underestimated how long it would take to build and ship new, revenue-generating products. Given that, and all we learned in 2019 about the pace of innovation, we decided to take a more conservative approach to projecting our revenue for 2020. We also agreed to a principle of living within our means, of not spending more than we earn for the foreseeable future.”

The laid-off employees received “generous exit packages” and outplacement support, Bakers writes. But it’s not yet clear which employees were laid off or what products they were working on.

“We know we must take bold steps to evolve and ensure the strength and longevity of our mission. Mozilla has a strong line of sight to future revenue generation, but we are taking a more conservative approach to our finances,” the memo continues. “This will enable us to pivot as needed to respond to market threats to internet health, and champion user privacy and agency.”