-file(STRINGS configure VERSION_STRING REGEX "PACKAGE_VERSION=.*")
-STRING(REGEX REPLACE "(.*)([\n*[.]]+).*" "\\2" ${VERSION_STRING} "${${VERSION_STRING}}")
-STRING(REGEX REPLACE "(PACKAGE_VERSION=')(.*)'" "\\2" VERSION_STRING ${VERSION_STRING})
+file(STRINGS configure.ac VERSION_STRING REGEX "AC_INIT.*")
+STRING(REGEX MATCH "[0-9]*[\\.][0-9]*[\\.][0-9]*" VERSION_STRING ${VERSION_STRING})