diff --git a/appveyor.yml b/appveyor.yml
index 016a9ee37..3c301a196 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -3,6 +3,7 @@ image: Visual Studio 2017
 
 
 before_build:
+  - git submodule -q update --init
   - cmd: dotnet --version
 
 build_script: