Index: configure.in
===================================================================
--- a/configure.in	(revision 239)
+++ b/configure.in	(working copy)
@@ -26,9 +26,9 @@
 if test "$with_cxxtools" = "yes"
 then
   AC_DEFINE(WITH_CXXTOOLS, [1], [defined if cxxtools is used])
+  AC_CHECK_HEADER([cxxtools/condition.h], , AC_MSG_ERROR([cxxtools headers not found]))
 fi
 
-AC_CHECK_HEADER([cxxtools/condition.h], , AC_MSG_ERROR([cxxtools headers not found]))
 AM_CONDITIONAL(WITH_CXXTOOLS, test "$with_cxxtools" = yes)
 
 # output