--- configure.ac.orig	2014-11-14 14:48:11 UTC
+++ configure.ac
@@ -212,7 +212,7 @@ AC_CACHE_CHECK(for pty/tty type, ptyttyl
     AC_CHECK_HEADERS([pty.h])    
  else if test x$ac_cv_func__getpty = xyes; then
     ptyttylib_cv_ptys=SGI4
- else if test -c /dev/ttyp20 -a ! -c /dev/ptmx; then 
+ else if test -c /dev/ttyp20 -a ! -c /nonexistent; then 
    ptyttylib_cv_ptys=SCO
  else if test -c /dev/ptym/clone; then
     ptyttylib_cv_ptys=HPUX
@@ -222,7 +222,7 @@ AC_CACHE_CHECK(for pty/tty type, ptyttyl
     ptyttylib_cv_ptys=PTC
  else if test -c /dev/ptc -a -d /dev/pts; then
     ptyttylib_cv_ptys=PTC
- else if test -c /dev/ptmx -a -c /dev/pts/0; then
+ else if test -c /nonexistent -a -c /dev/pts/0; then
     ptyttylib_cv_ptys=STREAMS
  else case "$host_os" in
          *cygwin*) ptyttylib_cv_ptys=STREAMS ;;