diff --git a/jobs/templates/swh-metrics.yaml b/jobs/templates/swh-metrics.yaml
index 25b6ab0..f46e564 100644
--- a/jobs/templates/swh-metrics.yaml
+++ b/jobs/templates/swh-metrics.yaml
@@ -1,29 +1,41 @@
 - job-template:
     name: swh-{name}/metrics
     node: swh-tox
 
     parameters:
       - string:
           name: BRANCH
           default: '{branch|master}'
     scm:
       - git:
           refspec: 'refs/heads/{branch|master}'
           url: https://forge.softwareheritage.org/source/swh-{name}.git
 
     numToKeep: 20
 
     triggers:
       - pollscm:
           cron: "H */3 * * *"
 
     wrappers:
       - timestamps
 
     builders:
+      - shell: |
+          if [ ! -f tox.ini ]
+          then cat >tox.ini <<EOF
+          [tox]
+          envlist=flake8
+          [testenv:flake8]
+          deps =
+            flake8
+          commands =
+            {{envpython}} -m flake8 {{posargs}}
+          EOF
+          fi
       - shell: mkdir -p reports
       - shell: python3 -m tox -e flake8
 
       - shell: python3 -m radon raw --json swh/ > reports/radon_raw.json
       - shell: python3 -m radon cc --json swh/ > reports/radon_cc.json
       - shell: python3 -m radon mi --json swh/ > reports/radon_mi.json