diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 3213065e4..c682f11e8 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -206,6 +206,6 @@ jobs:
         run: echo "tag=${GITHUB_REF#refs/*/}" >> $GITHUB_OUTPUT
       - name: Deploy demo.signalk.org at fly.io
         working-directory: ./fly_io/demo_signalk_org
-        run: flyctl deploy --remote-only --build-arg SK_VERSION=$tag
+        run: flyctl deploy --remote-only --build-arg SK_VERSION=${{ steps.vars.outputs.tag }}
         env:
           FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}