Fix appveyor.yml
diff --git a/appveyor.yml b/appveyor.yml
index e27cd9f..8227f8b 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -24,7 +24,7 @@
       PYTHON_ID: "pypy"
       PYTHON_EXE: pypy
 install:
-  - ps:
+  - ps: |-
       $env:PYTMP = "${env:TMP}\py";
       if (!(Test-Path "$env:PYTMP")) {
         New-Item -ItemType directory -Path "$env:PYTMP" | Out-Null;