Personally, I would consider silently modifying data structures to be a bug. I realize there may be reasons for Data::Dumper treating floats as strings, mostly because Perl relies on the math library used by the C compiler used to build Perl's executable, and it may be distracting to see 123.1 show up as 123.09999… in Data::Dumper's output. The most obvious fix is to modify the documentation ("Data::Dumper outputs all floating point values as strings so that 123.1 doesn't appear as 123.0999…"). This has the obvious advantage of avoiding the need to change any code.