There's been a lot of talk about the benefits of side hustling. From web developers to interior designers, taking on work outside of the nine-to-five is a lucrative way to earn extra cash while also expanding one's portfolio.

Employers can also reap the benefits of additional side work. Not only does this alleviate financial pressure on the employee, but it also provides valuable insight on just how challenging running a business can be. From client relations to invoicing, they may develop a deeper appreciation for their day job. Sounds like a win-win, right?

Well, not so fast. There's no arguing the benefits that can result from staff who balance freelancing with their full-time job. However, it's important to identify when the negatives start to outweigh the positives.

If you're beginning to wonder whether employees with side gigs are helping or hindering your business, ask yourself these five questions:

1. Have they become the competition?

These types of situations become troublesome if an employee is offering the same service as your company. It's particularly an issue if it's at a much lesser rate (and 99-percent of the time, it will be). What's preventing a client from hiring your employee for half the price?

Make it clear in your employee manual that contract work has to be reported to management immediately for approval. Transparency from both parties is key in order for this to (side) work.

2. Is it hindering their performance?

If they're a marketing coordinator by day and Uber driver by night, it may become a schedule that's too hard to maintain. Pulling 14 hour days between two jobs will take a toll on not just their job, but their mood, mindset, and focus.

While you may admire their work ethic, it becomes pointless if they burn out. Constantly late for work or falling asleep at their desk are issues you have to address.

3. Are they side hustling on your time?

This is obviously a big one. Doing their side hustle work during the hours you're paying them is a serious violation, and can even be terms for dismissal depending on the severity and frequency.

However, this doesn't mean you keep tabs by hovering over their shoulder. There's no need to ask I.T. to creep on their computer screen, because these types of scenarios won't take long to reveal themselves.

Missing deadlines, delayed emails, or rushed projects are all indicators that something's going on. As soon as you see the first slip up, schedule a one-on-one and get to the bottom of it.

4. Is there a conflict of interest?

Are they a full-time fitness trainer at your gym, but also teach classes at a competitor down the street? In a customer-facing role, your staff are the lifeline of your business. They're likely the reason your loyal clientele return day in and day out. So working their off-hours at the competition could be a big red flag.

5. Are they losing passion for their job?

There's no denying side hustling can become a threat. If they're starting to build a steady clientele, whose to say they won't hand in their resignation letter and strike out on their own?

You can't control your employees. If they've been bit by the entrepreneurial bug, you have to let them go. Forbidding them to side hustle because you're too afraid of losing them is not a valid reason to have the lawyers draft up a clause.

Instead, reflect on your own leadership and company culture that's made them want to freelance in the first place. Are your salaries too low? Are you stunting their growth? Are you providing supportive leadership?

Good leaders ask these questions in an exit-interview; great leaders ask them to prevent the exit-interview. Which one will you be?