diff --git a/sanity_check.sh b/sanity_check.sh
index ddcf37f..83dd204 100755
--- a/sanity_check.sh
+++ b/sanity_check.sh
@@ -2,7 +2,7 @@
 
 echo "Loading the Markdown files that have changed"
 
-for x in $(git diff --name-only HEAD main -- "*.md")
+for x in $(git diff --name-only origin/${GITHUB_HEAD_REF} main -- "*.md")
 do
   is_valid_md=$(python validate_markdown_metadata.py $x)
   if $is_valid_md; then