diff --git a/appveyor.yml b/appveyor.yml
index bfb8c60..0ab5ad4 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -16,7 +16,7 @@ environment:
     - PYTHON: "C:\\Python37-x64"
 
 install:
-  - "%PYTHON%\\python.exe -m pip install tox wheel pyinstaller"
+  - "%PYTHON%\\python.exe -m pip install tox wheel pyinstaller pil"
 
 build: off