diff --git a/.github/workflows/deploy-gh-pages.yaml b/.github/workflows/deploy-gh-pages.yaml
index 64d2732c5..4cfe2a6b6 100644
--- a/.github/workflows/deploy-gh-pages.yaml
+++ b/.github/workflows/deploy-gh-pages.yaml
@@ -11,6 +11,8 @@ jobs:
     steps:
       - name: 🛎️ Checkout
         uses: actions/checkout@v2
+        with:
+          fetch-depth: 0  # fetch all history so that last modified date-times are accurate
 
       - name: 🐍 Set up Python 3.9
         uses: actions/setup-python@v2