The tr/// Test case: use strict; use warnings; use utf8; use 5.010000; use autodie; binmode STDOUT, ':utf8'; my $x = "Perlα"; $x =~ tr/αα/βγ/; say "$^V $x"; reports: v5.16.0 Perlγ but it should place a beta as in 5.14: v5.14.2 Perlβ This is fixed in upstream with commit: commit cb6d347447b642c0af2d1a378f437459e42ef4f1 Author: Karl Williamson <public> Date: Mon Jun 11 09:56:56 2012 -0600 PATCH: [perl #113584] tr/// multiple transliterations Commit 4de6d205aeab9ec737ca35ba4eb61f37cebefc55 failed to take into consideration tr///.