I'm unfamilar with File::Find locking out files (i.e. Is this Windows?), so perhaps that's something to figure out. In any case here's a low tech solution is to post process them. For example, use File::Find to find the files and then append them to an array (or write them to a file if you have huge numbers of them). Once File::Find completes, then rename the files. Of course you run a greater risk of a file being changed between the time that you find them and the time you rename them, so YMMV.