You don't need --enable-lzw at all, it is enabled by default and can't be disabled. ImageMagick-6.0.5$ grep -lr lzw . ./PerlMagick/t/reference/filter/Raise.miff ./tests/Makefile.am ./tests/Makefile.in ./tests/Makefile.in.bak ./www/FAQ.html ./www/formats.html