diff --git a/appveyor.yml b/appveyor.yml
index d3fd81f5..8b29cc88 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -47,3 +47,4 @@ environment:
   global:
     NOT_CRAN: yes
     USE_RTOOLS: true
+    R_VERSION: release