diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 09dd889b91..d26f568a25 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -2176,15 +2176,14 @@ respdiff-third-party:
       artifacts: true
   script:
     - cd ${CI_PROJECT_DIR}
-    - mkdir version-under-test
-    - mv build version-under-test/
     - BASELINE=${CI_MERGE_REQUEST_TARGET_BRANCH_NAME:-$BIND_BASELINE_VERSION}
     - git fetch --unshallow origin ${BASELINE}
-    - git checkout FETCH_HEAD
+    - git worktree add baseline-build FETCH_HEAD
+    - cd baseline-build
     - *configure
     - meson compile -C build
     - cd "$CI_PROJECT_DIR"/bind9-qa/respdiff
-    - bash respdiff.sh -s named -q "${PWD}/100k_mixed.txt" -c 3 -w "${PWD}/rspworkdir" "${CI_PROJECT_DIR}/version-under-test" "${CI_PROJECT_DIR}/build/named"
+    - bash respdiff.sh -s named -q "${PWD}/100k_mixed.txt" -c 3 -w "${PWD}/rspworkdir" "${CI_PROJECT_DIR}" "${CI_PROJECT_DIR}/baseline-build/build/named"
 
 respdiff:recent-named:
   <<: *respdiff_recent_named