diff --git a/.forgejo/workflows/preview.yaml b/.forgejo/workflows/preview.yaml
index 52cc8e1..6948a60 100644
--- a/.forgejo/workflows/preview.yaml
+++ b/.forgejo/workflows/preview.yaml
@@ -11,7 +11,7 @@ jobs:
       - name: Environment setup
         run: |
           apk add git ikiwiki po4a perl-yaml-tiny tree nodejs jq coreutils curl
-          echo "GITHUB_PR_NAME=$(curl -Ls ${{ github.server_url }}/api/v1/repos/${{ github.repository }}/pulls/${{ github.ref_name }} | jq .title | tr ' ' '-' | tr -d ':' | tr -d '"' )" >> $GITHUB_ENV
+          echo "GITHUB_PR_NAME=$(curl -Ls ${{ github.server_url }}/api/v1/repos/${{ github.repository }}/pulls/${{ github.ref_name }} | jq .title | tr ' ' '-' | tr -d ':' | tr -d '"' | tr '[:upper:]' '[:lower:]' )" >> $GITHUB_ENV
       - name: Repo pull
         uses: actions/checkout@v4
         with: