Reminding teams to update diagrams, is it possible?

I'm my first ever project for a company I work for, as we've decided to document some of the more complex flows using flow charts & sequence diagrams, just so it's easier to onboard new developers but my own fear is that these diagrams will go stale.

Has anyone had this issue and if so how did you come up with a solution? I've thought about putting comments around the code which the diagrams will relate to or put a checklist on the PR to check if you need to update one of the architectural diagrams