diff --git a/.appveyor.yml b/.appveyor.yml
index 5713e6c..80d4c86 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -41,6 +41,7 @@ test_script:
 
 deploy_script:
   - ps: |
+      $ErrorActionPreference = 'Stop';
       if ( $env:APPVEYOR_PULL_REQUEST_NUMBER ) {
         Write-Host Nothing to deploy.
       } else {