You could enforce the process so that you only make code updates based on the documentation. So, if a new specification is requested, it must be made explicit i

You could enforce the process so that you only make code updates based on the documentation. So, if a new specification is requested, it must be made explicit in the documentation with a link to the issue next to it. Once the issue is closed, you can remove it from the documentation. This may be cumbersome to some, but I find it to be effective since you’re also confirming the business logic before implementing it.