diff --git a/.gitea/workflows/docker-build.yml b/.gitea/workflows/docker-build.yml
index 2ea9281..a14c00f 100644
--- a/.gitea/workflows/docker-build.yml
+++ b/.gitea/workflows/docker-build.yml
@@ -11,6 +11,8 @@ env:
   GO_VERSION: "1.25"
   REGISTRY: gitea.mrixs.me
   IMAGE_NAME: naviwatcher
+  # Convert repository owner to lowercase for Docker compatibility
+  REPO_OWNER_LOWER: ${{ toLower(gitea.repository_owner) }}
 
 jobs:
   test:
@@ -90,7 +92,7 @@ jobs:
           context: .
           push: true
           tags: |
-            ${{ env.REGISTRY }}/${{ gitea.repository_owner }}/${{ env.IMAGE_NAME }}:latest
-            ${{ env.REGISTRY }}/${{ gitea.repository_owner }}/${{ env.IMAGE_NAME }}:${{ github.sha }}
-          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ gitea.repository_owner }}/${{ env.IMAGE_NAME }}:buildcache
-          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ gitea.repository_owner }}/${{ env.IMAGE_NAME }}:buildcache,mode=max
\ No newline at end of file
+            ${{ env.REGISTRY }}/${{ env.REPO_OWNER_LOWER }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.REGISTRY }}/${{ env.REPO_OWNER_LOWER }}/${{ env.IMAGE_NAME }}:${{ github.sha }}
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.REPO_OWNER_LOWER }}/${{ env.IMAGE_NAME }}:buildcache
+          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.REPO_OWNER_LOWER }}/${{ env.IMAGE_NAME }}:buildcache,mode=max
\ No newline at end of file