diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 91f7a00..b65a8ca 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,7 +4,7 @@ image: python:3.7
 # only cache local items.
 variables:
   PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
-
+  GIT_SUBMODULE_STRATEGY: recursive # fetch submodule
 # Pip's cache doesn't store the python packages
 # https://pip.pypa.io/en/stable/reference/pip_install/#caching
 #