diff --git a/.github/workflows/release-webapp.yml b/.github/workflows/release-webapp.yml
index 76e6c8ba..624c0782 100644
--- a/.github/workflows/release-webapp.yml
+++ b/.github/workflows/release-webapp.yml
@@ -26,7 +26,7 @@ jobs:
       - name: Login to GitHub Container Registry
         run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u $ --password-stdin
       - name: "Container: Build image"
-        run: docker build -t $IMAGE_REPO:$IMAGE_TAG .
+        run: docker build -t $(echo $IMAGE_REPO | tr '[A-Z]' '[a-z]'):$IMAGE_TAG .
         env:
           DOCKER_BUILDKIT: 1
       - name: "Container: Publish image"