diff --git a/appveyor.yml b/appveyor.yml
index c6c14384e..d6c328f86 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -43,3 +43,7 @@ artifacts:
 
   - path: '\*_*.zip'
     name: Bits
+
+environment:
+  global:
+    USE_RTOOLS: true