diff --git a/.github/workflows/python.yml b/.github/workflows/python.yml
index d0ef156..187c346 100644
--- a/.github/workflows/python.yml
+++ b/.github/workflows/python.yml
@@ -9,6 +9,8 @@ jobs:
     runs-on: ubuntu-slim
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
       - uses: ./
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/README.md b/README.md
index 67d317d..454cc43 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,8 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@some-hash # v4.2.2
+        with:
+          persist-credentials: false
       - uses: schubergphilis/mcvs-python-action@some-hash # v0.2.1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
@@ -36,5 +38,9 @@ jobs:
 
 <!-- markdownlint-enable MD013 -->
 
+`persist-credentials: false` keeps the token out of `.git/config`, so
+third-party packages installed from `requirements.txt` cannot read it. The
+action receives the token only through the `token` input.
+
 Define the Python version of the project by adding it to a `.python-version`
 file.