diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index fefb7f032ceee37ed8882a012f6953d1e90d5e92..e825ca62ff263d06d34b84da126f9ba94f3455c3 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -16,7 +16,7 @@ check:
 pages:
   stage: deploy
   script:
-  - pip install sphinx sphinxcontrib-blockdiag blockdiag sphinxcontrib-restbuilder numpy
+  - pip install sphinx sphinxcontrib-blockdiag blockdiag sphinxcontrib-restbuilder numpy sphinx_rtd_theme
   - python setup.py install
   - sphinx-build -b html -d public/doctrees   doc public
   artifacts: