diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a337c2ef883e622ae0b944285679e824c2f5a3ba..5a17a5930c0098945dfffa348aeaf26b805a7e45 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -143,6 +143,7 @@ trigger lecture:
     strategy: depend
   variables:
     DUMUX_MERGE_REQUEST_SOURCE_BRANCH: $CI_MERGE_REQUEST_SOURCE_BRANCH_NAME
+    DUMUX_MERGE_REQUEST_SOURCE_PROJECT_URL: $CI_MERGE_REQUEST_SOURCE_PROJECT_URL
     DUMUX_MERGE_REQUEST_TARGET_BRANCH: $CI_MERGE_REQUEST_TARGET_BRANCH_NAME
     DUMUX_COMMIT_SHA: $CI_COMMIT_SHA
     DUMUX_REFERENCE_SHA: $CI_REFERENCE_SHA