diff --git a/appveyor.yml b/appveyor.yml
index b3504ad372..d4b1a4ee02 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,4 +1,5 @@
 version: "{build}"
+os: unstable
 
 environment:
   nodejs_version: "0.10"