diff --git a/.forgejo/workflows/build-images.yaml b/.forgejo/workflows/build-images.yaml
index a800bd2..61aef33 100644
--- a/.forgejo/workflows/build-images.yaml
+++ b/.forgejo/workflows/build-images.yaml
@@ -15,7 +15,7 @@ jobs:
   read-channels:
     runs-on: ci-os
     outputs:
-      channels: ${{ steps.export-channels.outputs.channels }}
+      channels: fromJson(${{ steps.export-channels.outputs.channels }})
     steps:
     - name: Checkout
       uses: actions/checkout@v4