diff --git a/Tools/xmlto/files/variants.Darwin b/Tools/xmlto/files/variants.Darwin
index 91b56a3..cb1c8c8 100644
--- a/Tools/xmlto/files/variants.Darwin
+++ b/Tools/xmlto/files/variants.Darwin
@@ -1 +1,2 @@
-xmlto/0.0.28	stable	b:getopt/1.1.6
+xmlto/0.0.28	stable		b:getopt/1.1.6
+xmlto/0.0.28-1	unstable	libxml2/2.9.9 b:getopt/1.1.6