diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 7fffe30..70bcc8c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -23,8 +23,9 @@ before_script:
 # This job tests if the book compiles gracefully after a new addition
 test-build:
   stage: test
-  only:
-    - main
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
+    - if: $CI_COMMIT_BRANCH == "main" && $CI_PIPELINE_SOURCE == "push"
   script:
     - pip install -r requirements.txt
     - jupyter-book clean book/