diff --git a/configuration/include/ac_check_envvar.m4 b/configuration/include/ac_check_envvar.m4
index e18a8da..164fd5c 100755
--- a/configuration/include/ac_check_envvar.m4
+++ b/configuration/include/ac_check_envvar.m4
@@ -9,11 +9,12 @@
 dnl
 
 AC_DEFUN([AC_CHECK_ENVVAR],[dnl
-AC_MSG_CHECKING([value of $1])
-if test "x@S|@$1" != "x"; then
-	AC_MSG_RESULT([@S|@$1])
+AC_MSG_CHECKING([$1])
+if test -z @S|@$1; then
+	AC_MSG_RESULT([no])
+	AC_MSG_WARN([required environment variable $1 not defined])
 else
-	AC_MSG_WARN([not defined! (please fix)])
+	AC_MSG_RESULT([@S|@$1])
 fi
 ])