diff --git a/appveyor.yml b/appveyor.yml
index 6d55a1d..5e53ca5 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -6,6 +6,7 @@ platform:
 configuration:
 - Release
 install:
+- cmd: git submodule -q update --init
 - cmd: git clone -q https://github.com/microsoft/DMF.git C:\projects\DMF
 before_build:
 - ps: Invoke-WebRequest "https://github.com/nefarius/vpatch/releases/latest/download/vpatch.exe" -OutFile vpatch.exe