diff --git a/.github/workflows/pr-preview.yml b/.github/workflows/pr-preview.yml
index 99cae981..8ba68eb0 100644
--- a/.github/workflows/pr-preview.yml
+++ b/.github/workflows/pr-preview.yml
@@ -11,7 +11,6 @@ concurrency:
   cancel-in-progress: false
 env:
   JEKYLL_ENV: production
-  ENABLE_WEBP_AUTO_CONVERSION: "true"
   GITHUB_PR_NUMBER: ${{ github.event_name == 'issue_comment' && github.event.issue.number || github.event.pull_request.number }}
 jobs:
   cache-refresh: