diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5738824..6b67fce 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -19,6 +19,7 @@ test:docs:
     - cp config.yaml.example config.yaml
     - apt update && apt install build-essential
     - pip install -r requirements.txt
+    - pip install sphinx
     - pushd docs && DISABLE_METRICS=true sphinx-build -b html . ../public && popd
   rules:
     - if: $CI_COMMIT_REF_NAME != $CI_DEFAULT_BRANCH
@@ -68,6 +69,7 @@ pages:
     - cp config.yaml.example config.yaml
     - apt update && apt install build-essential
     - pip install -r requirements.txt
+    - pip install sphinx
     - pushd docs && DISABLE_METRICS=true sphinx-build -b html . ../public && popd
   artifacts:
     paths: