Mentioning side hustle to new employer

I’m about to join a large company in the Netherlands, and their employment contract includes a clause requiring written approval for any unrelated activity.

I have a KvK-registered side business that I occasionally use for freelance projects. It’s unrelated to the company’s domain, I work on it outside office hours, and it doesn’t interfere with my job.

Has anyone gone through the process of disclosing something like this?

• Do companies generally approve this kind of thing if it’s separate?
• Is it better to bring it up proactively, or could that cause unnecessary complications?

Looking for advice from others in NL who’ve had to navigate this kind of clause, especially with freelance or side work on the books.