diff --git a/roles/pycobertura-diff/tasks/main.yaml b/roles/pycobertura-diff/tasks/main.yaml
index 64726eb..444d525 100644
--- a/roles/pycobertura-diff/tasks/main.yaml
+++ b/roles/pycobertura-diff/tasks/main.yaml
@@ -1,17 +1,17 @@
+- name: Place for new version of sources
+  file:
+    path: "{{ new_source_prefix }}"
+    state: directory
+
 - name: Prepare copy of the new version of sources
-  shell: |
-    set -ex
-    NEW_WORK={{ ansible_user_dir }}/new
-    mkdir "${NEW_WORK}"
-    NEW_SRCDIR=${NEW_WORK}/{{ zuul.project.short_name }}
-    pushd {{ zuul.project.src_dir }}
-    git worktree add "${NEW_SRCDIR}" {{ zuul.branch }}
-    popd
+  command: git worktree add {{ new_source_prefix }}/{{ zuul.project.short_name }} {{ zuul.branch }}
+  args:
+    chdir: "{{ zuul.project.src_dir }}"
 
 - name: Retrieve coverage from parent jobs
   get_url:
     url: "{{ item.url }}"
-    dest: "{{ ansible_user_dir }}/new/coverage.xml"
+    dest: "{{ new_source_prefix }}/coverage.xml"
   when:
     - item.metadata is defined
     - item.metadata.type is defined
@@ -23,9 +23,9 @@
     set -ex
     PATH=${PATH}:~/.local/bin
     pycobertura show --format html --output "{{ ansible_user_dir }}/zuul-output/logs/coverage.html" \
-      --source "{{ ansible_user_dir }}/new/{{ zuul.project.short_name }}" "{{ ansible_user_dir }}/new/coverage.xml"
+      --source "{{ new_source_prefix }}/{{ zuul.project.short_name }}" "{{ new_source_prefix }}/coverage.xml"
     pycobertura diff --format html --output "{{ ansible_user_dir }}/zuul-output/logs/coverage-diff.html" \
       --source1 "{{ zuul.project.src_dir }}" "{{ coverage_xml_dir }}/coverage.xml" \
-      --source2 "{{ ansible_user_dir }}/new/{{ zuul.project.short_name }}" "{{ ansible_user_dir }}/new/coverage.xml"
+      --source2 "{{ new_source_prefix }}/{{ zuul.project.short_name }}" "{{ new_source_prefix }}/coverage.xml"
     sed -e 's;^  </body>$;    <p>Show <a href="coverage.html">final coverage</a> only</p>\n  </body>;' \
       -i "{{ ansible_user_dir }}/zuul-output/logs/coverage-diff.html"
diff --git a/zuul.yaml b/zuul.yaml
index cf2f5a6..9524560 100644
--- a/zuul.yaml
+++ b/zuul.yaml
@@ -54,6 +54,7 @@
     failure-url: coverage-diff.html
     vars:
       coverage_xml_dir: "{{ ansible_user_dir }}/build"
+      new_source_prefix: "{{ ansible_user_dir }}/new"
 
 - job:
     name: f29-gcc-asan