diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c1f9564d4906d30bda6039b1fde34c0a6fbbe289..5f591113ab24e634dec5e963cf35d280c056e756 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,6 +5,7 @@ pages:
   - apk --no-cache add py3-pip python-dev
   - pip install sphinx
   - pip install sphinx-autodoc-typehints
+  - pip install sphinx_rtd_theme
   - apk --no-cache add make
   - cd docs && make html
   - mv build/html/ public/