diff --git a/.github/workflows/build_push.yml b/.github/workflows/build_push.yml
index 75cfe72..64e869e 100644
--- a/.github/workflows/build_push.yml
+++ b/.github/workflows/build_push.yml
@@ -28,6 +28,12 @@ jobs:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Sanitize repo namespace
+        uses: actions/github-script@v6
+        id: gh_repo_ns
+        with:
+          result-encoding: string
+          script: return 'ghcr.io/${{ github.repository_owner }}'.toLowerCase()
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v2
       - name: Create VoID Description
@@ -45,5 +51,5 @@ jobs:
           tags: |
             ${{ secrets.DOCKERHUB_USERNAME }}/madb-fuseki:${{ inputs.dataset_version }}
             ${{ secrets.DOCKERHUB_USERNAME }}/madb-fuseki:${{ inputs.dataset_version }}-fuseki${{ matrix.fuseki_version }}
-            ghcr.io/${{ github.repository_owner }}/madb-fuseki:${{ inputs.dataset_version }}
-            ghcr.io/${{ github.repository_owner }}/madb-fuseki:${{ inputs.dataset_version }}-fuseki${{ matrix.fuseki_version }}
+            ${{ steps.gh_repo_ns.outputs.result }}/madb-fuseki:${{ inputs.dataset_version }}
+            ${{ steps.gh_repo_ns.outputs.result }}/madb-fuseki:${{ inputs.dataset_version }}-fuseki${{ matrix.fuseki_version }}