diff --git a/appveyor-windows.yml b/appveyor-windows.yml
index 65acce8..1d6018c 100644
--- a/appveyor-windows.yml
+++ b/appveyor-windows.yml
@@ -32,6 +32,8 @@ install:
   - haxelib git faxe https://github.com/uhrobots/faxe
   - haxelib git polymod https://github.com/larsiusprime/polymod.git
   - haxelib git discord_rpc https://github.com/Aidan63/linc_discord-rpc
+  - haxelib git extension-webm https://github.com/KadeDev/extension-webm
+  - lime rebuild extension-webm windows
   - haxelib install linc_luajit
   - haxelib list