diff --git a/configure.in b/configure.in
index 0dd7e0a..15f5ee1 100644
--- a/configure.in
+++ b/configure.in
@@ -151,6 +151,11 @@
 ])
 AC_MSG_RESULT($with_cxx)
 
+if test "$with_cxx" = "yes"
+then
+	AC_ERROR(must supply a compiler when using --with-cxx)
+fi
+
 dnl The following fragment works similar to AC_PROG_CXX.
 dnl It does not fail if CXX is not found, and it is not executed if 
 dnl --without-cxx was given.