diff --git a/.github/workflows/docker-publish.yml b/.github/workflows/docker-publish.yml
index 90987d2..34633ce 100644
--- a/.github/workflows/docker-publish.yml
+++ b/.github/workflows/docker-publish.yml
@@ -18,6 +18,9 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      - name: Compute lowercase owner
+        run: echo "OWNER_LC=${GITHUB_REPOSITORY_OWNER,,}" >> "$GITHUB_ENV"
+
       - name: Login to GHCR
         uses: docker/login-action@v3
         with:
@@ -31,8 +34,8 @@ jobs:
           context: ./backend
           push: true
           tags: |
-            ghcr.io/${{ github.repository_owner }}/family_budget-backend:latest
-            ghcr.io/${{ github.repository_owner }}/family_budget-backend:${{ github.sha }}
+            ghcr.io/${{ env.OWNER_LC }}/family_budget-backend:latest
+            ghcr.io/${{ env.OWNER_LC }}/family_budget-backend:${{ github.sha }}
 
       - name: Build and push frontend image
         uses: docker/build-push-action@v6
@@ -40,5 +43,5 @@ jobs:
           context: ./frontend
           push: true
           tags: |
-            ghcr.io/${{ github.repository_owner }}/family_budget-frontend:latest
-            ghcr.io/${{ github.repository_owner }}/family_budget-frontend:${{ github.sha }}
+            ghcr.io/${{ env.OWNER_LC }}/family_budget-frontend:latest
+            ghcr.io/${{ env.OWNER_LC }}/family_budget-frontend:${{ github.sha }}