Nearly two in five (39%) of U.S. adults have a side hustle — and despite the fact that many of them use the extra cash earned to pay essential bills, not every 9-5 employer is as supportive as the next.

That’s why side hustle expert and remote work advocate Daniella Flores told CNBC Make It that employees should take a close look at their employer’s policy on the subject — and potentially consult with an employment lawyer if they’re unsure how much information must be disclosed.

However, some employers might actually encourage their employees to start their own side hustles. Ross Buhrdorf, CEO of ZenBusiness, a fully remote company that provides an all-one-one platform and guidance for small business owners, is one of them.