diff --git a/appveyor.yml b/appveyor.yml
index d44acf2f73..9c83b1f9d1 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,6 +1,7 @@
 version: 1.0.{build}
 os: Visual Studio 2015
 before_build:
+- git submodule update --init
 - nuget restore Perspex.sln
 build:
   project: Perspex.sln