diff --git a/.github/workflows/prune-attachments.yml b/.github/workflows/prune-attachments.yml
index 8db1476fb..401096279 100644
--- a/.github/workflows/prune-attachments.yml
+++ b/.github/workflows/prune-attachments.yml
@@ -23,6 +23,7 @@ jobs:
         with:
           ref: gh-pages
           lfs: true
+          fetch-depth: 0 # Get full history to check file ages
         env:
           GIT_LFS_SKIP_SMUDGE: 1 # Don't actually download LFS content