(Reuters) – Slack Technologies Inc (WORK.N) on Thursday withdrew its forecast for 2021 billings citing uncertainty driven by the COVID-19 pandemic, sending shares down 16% after market hours.

The workplace messaging company’s total operating expenses in the first quarter jumped 63% to $252.2 million (200 million pounds). (reut.rs/3dLITgh)

Social distancing protocols have led many companies to rapidly adopt remote work, expanding the market for apps that allow workers to stay in touch and boosting Wall Street expectations for companies such as Slack.

However, the economic damage brought on by the health crisis might also force companies to cut back on technology spending, Slack had warned in March.

This has also led to fierce competition, with players like Zoom and Microsoft’s Teams vying for a larger share of the workplace messaging market.

Slack’s first-quarter revenue rose 50% to $201.7 million from a year earlier, above analysts’ average estimate of $188.1 million, according to IBES data from Refinitiv.