> I have a test-case here if anyone would like to look at it and give me a "Works For Me" or "Your code's wrong" or something. I got the same wrong output as you. regex-base: 0.93.2 regex-pcre: 0.94.4 GHC: 7.10.3 LANG: en_GB.UTF-8 LANGUAGE: en_GB:en system: debian 8.5 (jessie) configUTF8: returns True pcre lib: 8.35 2014-04-04