-# Compute minor/major version numbers
-major_version=`echo AC_PACKAGE_VERSION | sed 's/\..*//'`
-minor_version=`echo AC_PACKAGE_VERSION | sed 's/.*\.//' | sed 's/^0//'`
+# Compute minor/major/patchlevel version numbers
+major_version=$(echo AC_PACKAGE_VERSION | sed 's/\([^.]\)*\.\([^.]*\)\.\([^.]*\)/\1/)')
+minor_version=$(echo AC_PACKAGE_VERSION | sed 's/\([^.]\)*\.\([^.]*\)\.\([^.]*\)/\2/)')
+patchlevel_version=$(echo AC_PACKAGE_VERSION | sed 's/\([^.]\)*\.\([^.]*\)\.\([^.]*\)/\3/)')