diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index fc180ef5e9aeb695579163dd0ec54a728831c574..b8a4cc826d9a2a39c4bbac92babf785224c4a5a9 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -61,6 +61,7 @@ pages:
   extends: test
   stage: production
   script:
+    - unset SITE_URL # This is only used in the test job.
     - mkdocs build --strict --verbose --site-dir public
     # Expose services.yml for consumption by other apps/services.
     - mkdir -p public/api