diff --git a/appveyor.yml b/appveyor.yml
index d605c008c..5416916ad 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -15,7 +15,7 @@ before_test:
 - ps: Invoke-WebRequest "https://github.com/fpco/minghc/blob/master/bin/7z.dll?raw=true" -OutFile 7z.dll
 - 7z x -oc:\\stack stack.zip
 - move c:\\stack\\stack.exe stack.exe
-- stack setup
+- stack setup --arch=x86_64
 
 clone_folder: "c:\\pandoc"
 environment: