# older flex versions don't support is (see automake bug#11524 and
# bug#12836). Skip this test if such an old flex version is detected.
$LEX --help | grep '.*--header-file' \
- || skip_ "flex doesn't support the --header-file' option"
+ || skip_ "flex doesn't support the '--header-file' option"
cat >> configure.ac << 'END'
AC_PROG_CC