diff --git a/appveyor.yml b/appveyor.yml
index e84bf6c88..aa69719d8 100755
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,5 +1,5 @@
 os:
-- Unstable
+- Windows Server 2012 R2
 
 platform:
 - x86