[racket] Code compiled for version ~a, not ~a

I test my code against the many different versions of DrRacket, which 
means I switch version several times a day.

Each time I launch a different version of DrRacket, I inevitably forget 
to recompile some library that's in my PLTCOLLECTS, or in my raco link 
table, which means I get lots of "code compiled for version ~a, not ~a" 
errors.

Is there a way to tell Racket to go ahead and recompile these zos as it 
finds them?