diff --git a/.github/workflows/validate.yml b/.github/workflows/validate.yml
index d00019d..bc002a3 100644
--- a/.github/workflows/validate.yml
+++ b/.github/workflows/validate.yml
@@ -51,7 +51,13 @@ jobs:
       - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744
       - name: List Changed Board Files
         id: list-changed-files
-        run: echo "all_changed_files=`git diff main --name-only --diff-filter=ACMR | xargs`" >> "$GITHUB_OUTPUT"
+        run: |
+          # also fetch main to diff against
+          git fetch --depth=1 origin main
+          # list Added, Copied, Modified, and Renamed files
+          ACMR_FILES=`git diff origin/main --name-only --diff-filter=ACMR | xargs`
+          # GitHub Actions output ritual
+          echo "all_changed_files=$ACMR_FILES" >> "$GITHUB_OUTPUT"
 
   validate-expected-filenames:
     name: Validate Filenames