diff --git a/.gitea/workflows/backend_build-deploy-stg.yaml b/.gitea/workflows/backend_build-deploy-stg.yaml
index b99d605..527272a 100644
--- a/.gitea/workflows/backend_build-deploy-stg.yaml
+++ b/.gitea/workflows/backend_build-deploy-stg.yaml
@@ -13,6 +13,6 @@ jobs:
     uses: ./.gitea/workflows/workflow_build-image.yaml
     with:
       # sets a unique tag for each commit in the PR - this gets deployed to a separate application instance using argocd
-      tag: ${{ github.head_ref }}-{{ github.sha }}
+      tag: ${{ github.head_ref }}-${{ github.sha }}
     secrets:
       PACKAGE_REGISTRY_ACCESS: ${{ secrets.PACKAGE_REGISTRY_ACCESS }}