diff --git a/configh.in b/configh.in
index 92bbb52950812b8b175059f4c831f72a038f7204..c0781359f90da30d2ebc48623a592bb267577261 100644
--- a/configh.in
+++ b/configh.in
@@ -1,5 +1,5 @@
 /*
- * "$Id: configh.in,v 1.11.2.9 2001/04/27 14:39:27 easysw Exp $"
+ * "$Id: configh.in,v 1.11.2.10 2001/04/27 17:00:23 easysw Exp $"
  *
  * Configuration file for the Fast Light Tool Kit (FLTK).
  * @configure_input@
@@ -122,26 +122,26 @@
  * Where is <dirent.h> (used only by fl_file_chooser and scandir).
  */
 
-#define HAVE_DIRENT_H 1
-#define HAVE_SYS_NDIR_H 0
-#define HAVE_SYS_DIR_H 0
-#define HAVE_NDIR_H 0
-#define HAVE_SCANDIR 0
+#undef HAVE_DIRENT_H
+#undef HAVE_SYS_NDIR_H
+#undef HAVE_SYS_DIR_H
+#undef HAVE_NDIR_H
+#undef HAVE_SCANDIR
 
 /*
  * Possibly missing sprintf-style functions:
  */
 
-#define HAVE_VSNPRINTF 0
-#define HAVE_SNPRINTF 0
-#define HAVE_VSPRINTF 0
+#undef HAVE_VSNPRINTF
+#undef HAVE_SNPRINTF
+#undef HAVE_VSPRINTF
 
 /*
  * String functions and headers...
  */
 
-#define HAVE_STRINGS_H 0
-#define HAVE_STRCASECMP 0
+#undef HAVE_STRINGS_H
+#undef HAVE_STRCASECMP
 
 /*
  * HAVE_SYS_SELECT_H:
@@ -149,7 +149,7 @@
  * Whether or not select() call has its own header file.
  */
 
-#define HAVE_SYS_SELECT_H 0
+#undef HAVE_SYS_SELECT_H
 
 /*
  * HAVE_SYS_STDTYPES_H:
@@ -157,7 +157,7 @@
  * Whether or not we have the <sys/stdtypes.h> header file.
  */
 
-#define HAVE_SYS_STDTYPES_H 0
+#undef HAVE_SYS_STDTYPES_H
 
 /*
  * USE_POLL:
@@ -168,5 +168,5 @@
 #define USE_POLL 0
 
 /*
- * End of "$Id: configh.in,v 1.11.2.9 2001/04/27 14:39:27 easysw Exp $".
+ * End of "$Id: configh.in,v 1.11.2.10 2001/04/27 17:00:23 easysw Exp $".
  */
diff --git a/configure.in b/configure.in
index 9aa955e23d008638a57e56af5430c85f812c1821..c0da00f6f86d1438c293b2d95d9f35248e95c4f7 100644
--- a/configure.in
+++ b/configure.in
@@ -1,7 +1,7 @@
 dnl -*- sh -*-
 dnl the "configure" script is made from this by running GNU "autoconf"
 dnl
-dnl "$Id: configure.in,v 1.33.2.28 2001/04/27 14:39:27 easysw Exp $"
+dnl "$Id: configure.in,v 1.33.2.29 2001/04/27 17:00:23 easysw Exp $"
 dnl
 dnl Configuration script for the Fast Light Tool Kit (FLTK).
 dnl
@@ -135,8 +135,8 @@ else
 fi
 
 AC_HEADER_DIRENT
-AC_CHECK_HEADER(sys/select.h)
-AC_CHECK_HEADER(sys/stdtypes.h)
+AC_CHECK_HEADER(sys/select.h,AC_DEFINE(HAVE_SYS_SELECT_H))
+AC_CHECK_HEADER(sys/stdtypes.h,AC_DEFINE(HAVE_SYS_SELECT_H))
 AC_CHECK_FUNC(scandir,
     if test "$uname" = SunOS -o "$uname" = QNX; then
         echo Not using $uname scandir emulation function.
@@ -156,7 +156,7 @@ AC_CHECK_FUNC(snprintf,
         AC_DEFINE(HAVE_SNPRINTF)
     fi)
 AC_CHECK_FUNCS(vsprintf)
-AC_CHECK_HEADER(strings.h)
+AC_CHECK_HEADER(strings.h,AC_DEFINE(HAVE_STRINGS_H))
 AC_CHECK_FUNCS(strcasecmp)
 
 dnl Check for X11...
@@ -372,5 +372,5 @@ AC_CONFIG_HEADER(config.h:configh.in)
 AC_OUTPUT(makeinclude)
 
 dnl
-dnl End of "$Id: configure.in,v 1.33.2.28 2001/04/27 14:39:27 easysw Exp $".
+dnl End of "$Id: configure.in,v 1.33.2.29 2001/04/27 17:00:23 easysw Exp $".
 dnl