diff --git a/appveyor.yml b/appveyor.yml
index 56829a53ff..f2a88d28b6 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,5 +1,5 @@
 version: 1.1.1.{build}
-
+os: unstable
 configuration:
     Release