use a better test

diff --git a/doc/Makefile.am b/doc/Makefile.am
index cf43a27..eb0404f 100644 (file)
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -31,7 +31,8 @@ $(INFO_DEPS): $(EXTRA_DIST)
 # List words/regexps here that should not appear in the texinfo documentation.
 check-texinfo:
        grep timezone $(srcdir)/*.texi && exit 1 || :
-       perl -ne '/\bPOSIX\b/i && !/\@acronym{POSIX}/ and print,exit 1' \
+       @PERL@ -ne \
+         '/\bPOSIX\b/ && !/\@acronym{POSIX}/ || /{posix}/ and print,exit 1' \
          $(srcdir)/*.texi 2> /dev/null && : || exit 1
 
 check: check-texinfo