diff --git a/.github/workflows/archive-validation.yml b/.github/workflows/archive-validation.yml
index fafc6660..2a4b2718 100644
--- a/.github/workflows/archive-validation.yml
+++ b/.github/workflows/archive-validation.yml
@@ -27,9 +27,11 @@ jobs:
 
       - id: number-of-changed-files
         run: |
-          echo "NO_OF_FILES_CHANGED_IN_ROOT=$(.ci/github/files_between_commits.sh $GITHUB_REF $GITHUB_SHA | .ci/github/number_of_files_changed_in_root.sh)" >> $GITHUB_ENV
+          echo "NO_OF_FILES_CHANGED_IN_ROOT=$(.ci/github/files_between_commits.sh $GITHUB_BASE_REF $GITHUB_SHA | .ci/github/number_of_files_changed_in_root.sh)" >> $GITHUB_ENV
 
       - run: echo $NO_OF_FILES_CHANGED_IN_ROOT
+      - run: echo $GITHUB_BASE_REF
+      - run: echo $GITHUB_HEAD_REF
 
 #      - run: |
 #          git archive -o archive.tar $GITHUB_SHA && sh .ci/github/validate_archive.sh archive.tar