diff --git a/.github/workflows/docker-image.yml b/.github/workflows/docker-image.yml
index 78839ef..12a802f 100644
--- a/.github/workflows/docker-image.yml
+++ b/.github/workflows/docker-image.yml
@@ -26,9 +26,12 @@ jobs:
         username: ${{ github.repository_owner }}
         password: ${{ secrets.GITHUB_TOKEN }}
 
+    - name: Set repository owner to lowercase
+      run: echo "REPO_OWNER=$(echo ${{ github.repository_owner }} | tr '[:upper:]' '[:lower:]')" >> $GITHUB_ENV
+
     - name: Build and push Docker image
       uses: docker/build-push-action@v2
       with:
         context: .
         push: true
-        tags: ghcr.io/${{ github.repository_owner }}/posh-rest:latest
+        tags: ghcr.io/${{ env.REPO_OWNER }}/posh-rest:latest