diff --git a/.github/workflows/build_and_test.yaml b/.github/workflows/build_and_test.yaml
index 07278f965..d179d5ed9 100644
--- a/.github/workflows/build_and_test.yaml
+++ b/.github/workflows/build_and_test.yaml
@@ -41,6 +41,7 @@ jobs:
     runs-on: ${{ inputs.runner || 'ubuntu-22.04' }}
     env:
       CACHE_PATH: /tmp/cache
+      CI_REPO: EVerest/everest-core
     steps:
       - name: Format branch name for cache key
         run: |
@@ -55,24 +56,17 @@ jobs:
           restore-keys: |
             compile-${{ env.branch_name_for_cache }}-
             compile-
-      - name: Checkout from `everest-core` the `.ci/` directory (reusable workflow mode, see https://stackoverflow.com/a/74123003/1168315)
+      - name: Checkout `${{ env.CI_REPO }}` (to only get the `.ci/` directory if reusable workflow mode, see https://stackoverflow.com/a/74123003/1168315)
         uses: actions/checkout@v4
         with:
-          sparse-checkout: |
-            .ci
-          repository: EVerest/everest-core
+          path: ci-repo
+          repository: ${{ env.CI_REPO }}
           ref: CI/reusable-workflow  # TODO get reference in general, see https://stackoverflow.com/questions/74784735 resp. https://github.com/actions/toolkit/issues/1264
-      - name: Move `.ci/` to `/tmp` and remove `everest-core`
-        run: |
-          mv .ci /tmp
-          pwd && ls -hal .
-          cd ..
-          pwd && ls -hal .
-          rm -rf everest-core
-          pwd && ls -hal .
-      - name: Checkout repo ${{ inputs.repository || 'EVerest/everest-core' }}
+      - name: Checkout repo ${{ inputs.repository }}
+        if: ${{ github.repository != env.CI_REPO }}
         uses: actions/checkout@v4
         with:
+          path: source
           repository: ${{ inputs.repository }}
           ref: ${{ inputs.repository_ref }}
       - name: Pull build-kit image
@@ -82,11 +76,12 @@ jobs:
       - name: Build and install
         env:
           CMAKE_FLAGS_EXTRA: ${{ inputs.cmake_flags_extra || '-DEVC_ENABLE_CCACHE=1 -DISO15118_2_GENERATE_AND_INSTALL_CERTIFICATES=OFF' }}
+        working-directory: source
         run: |
           ls -hal .
           docker run \
             --volume "${CACHE_PATH:?}:/ext/cache" \
-            --volume "/tmp/.ci:/.ci" \
+            --volume "ci-repo/.ci:/.ci" \
             --volume "$(pwd):$(pwd)" \
             --workdir "$(pwd)" \
             --env CMAKE_FLAGS_EXTRA="${CMAKE_FLAGS_EXTRA:?}" \
@@ -100,20 +95,22 @@ jobs:
           path: build/CMakeFiles/
       - name: Unit tests
         if: ${{ inputs.unit_tests || false }}
+        working-directory: source
         run: |
           docker commit build-container unit-tests-image
           trap "cp build/Testing/Temporary/LastTest.log /tmp/ctest-report" EXIT
           docker run \
+            --volume "ci-repo/.ci:/.ci" \
             --volume "$(pwd):$(pwd)" \
-            --volume "/tmp/.ci:/.ci" \
             --workdir "$(pwd)" \
             --name test-container \
             unit-tests-image /.ci/build-kit/unit_tests.sh
       - name: Integration tests
         if: ${{ inputs.integration_tests || true }}
-        working-directory: /tmp/.ci/e2e/
+        working-directory: source
         run: |
           docker commit build-container integration-tests-image
+          pushd ci-repo/.ci/e2e/
           docker-compose run e2e-test-server scripts/tests.sh
       - name: FIXME make all files in `cache/` readable
         # FIXME Workaround for non-readable certs in `cache/josev/[ID]/Josev/iso15118/shared/pki/iso15118_2/certs . See https://github.com/EVerest/everest-core/actions/runs/7286554315/job/19855498928#step:13:10