diff --git a/.drone.yml b/.drone.yml
index 2c38742..3bec02f 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -5,4 +5,6 @@ steps:
   - name: check documentation build
     image: rust:1.49-slim-buster
     commands:
+      - git submodule init
+      - git submodule update --recursive --remote
       - ./build.sh