diff --git a/appveyor.yml b/appveyor.yml
index c593022a88..6dd6f00bc0 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,5 +1,7 @@
 version: '{build}'
 
+os: Previous Visual Studio 2015
+
 branches:
   only:
   - master