Employees don’t necessarily tell their employers about side gigs, according to a survey from Clutch, a B2B ratings and reviews company. It found 36% of workers have a side job, but as many as 25% of them don’t tell their managers at their main jobs.

And more workers may take side gigs, with 17% saying they are actively looking for one.

Clutch also noted that without formal policies in the workplace, employees have little or no legal requirement to disclose their work in the gig economy.

And it’s not unreasonable for employees to not disclose their side gig if it doesn’t impact their regular work, according to Alison Green, a management consultant who pens the Ask a Manager blog.

“If it’s not a conflict of interest and it’s not getting in the way of the person’s work, the manager should stay out of it,” Green said.

Clutch’s survey included 521 workers at US companies.