diff --git a/.github/workflows/validate_markdown.yml b/.github/workflows/validate_markdown.yml
index 25e3af9..9a2455b 100644
--- a/.github/workflows/validate_markdown.yml
+++ b/.github/workflows/validate_markdown.yml
@@ -49,6 +49,6 @@ jobs:
     - name: Markdown links
       uses: gaurav-nelson/github-action-markdown-link-check@v1
       with:
-        check-modified-files-only: 'yes'
+        CHECK_MODIFIED_FILES: yes