diff --git a/.github/workflows/python-mutation-tests.yml b/.github/workflows/python-mutation-tests.yml
index 38a60e1c8..2324d85ee 100644
--- a/.github/workflows/python-mutation-tests.yml
+++ b/.github/workflows/python-mutation-tests.yml
@@ -7,11 +7,11 @@ on:
   # Todo; remove the push, they take to long
   push:
     branches:
-      - add-mutation-testing-with-cosmic-ray
+      - add-mutation-testing
 
 jobs:
-  tests:
-    name: Python mutation tests
+  cosmic-ray:
+    name: Python mutation tests - Cosmic Ray
     runs-on: ubuntu-latest
 
     strategy:
@@ -37,7 +37,6 @@ jobs:
 
       - name: Run mutation tests
         run: |
-          # Todo: Can we make it faster in GitHub Actions
           # Todo: Drop the --force, it just here for easy local copy and paste
           poetry run cosmic-ray init setup.cfg cosmic-ray.sqlite --force
           echo "Initialised"
@@ -46,5 +45,36 @@ jobs:
       - name: Report results
         # Todo: Only show failures https://github.com/sixty-north/cosmic-ray/issues/561
         run: poetry run cr-report cosmic-ray.sqlite --show-diff
-        env:
-          PYTHON_VERSION: ${{ matrix.python-version }}
+
+  mutmut:
+    name: Python mutation tests - mutmut
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.12"]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Display Python version
+        run: python --version
+
+      - name: Install dependencies
+        run: |
+          pip install poetry
+          poetry install
+
+      - name: Run mutation tests
+        run: |
+          poetry run mutmut run
+
+      - name: Report results
+        # Todo: Only show failures https://github.com/sixty-north/cosmic-ray/issues/561
+        run: poetry run mutmut results
diff --git a/pytest.ini b/pytest.ini
index 59117759d..7b1fb739e 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -1,9 +1,9 @@
 [pytest]
 env =
     AWS_DEFAULT_REGION=eu-west-2
-addopts = --tb=short --numprocesses auto --dist loadgroup
+; addopts = --tb=short --numprocesses auto --dist loadgroup
 ; You may need to use the addopts setting below to unbreak debugging in your IDE
-; addopts = --tb=short
+addopts = --tb=short
 
 filterwarnings =
     ignore::UserWarning:moto.cloudformation.parsing.*
diff --git a/setup.cfg b/setup.cfg
index 204e5d129..7df75fb6d 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,19 +1,23 @@
 [cosmic-ray]
-module-path = "utils"
+module-path = utils
 timeout = 10.0
 excluded-modules = ["**/node_modules/**/*"]
-test-command = "poetry run pytest tests/utils"
+test-command = poetry run pytest tests/utils
 
 [cosmic-ray.distributor]
 name = "local"
 ; name = "http"
 
 [cosmic-ray.distributor.http]
-worker-urls = ["http://localhost:9876","http://localhost:9877","http://localhost:9878","http://localhost:9879"]
+worker-urls =
+    http://localhost:9876
+    http://localhost:9877
+    http://localhost:9878
+    http://localhost:9879
 
 [mutmut]
-paths_to_mutate = "utils/"
-runner="poetry run pytest tests/utils"
-tests_dir = "tests/utils"
+paths_to_mutate = utils
+runner= poetry run pytest tests/utils
+tests_dir = tests/utils
 also_copy=
-    "dbt_platform_helper"
+    dbt_platform_helper