diff --git a/.forgejo/workflows/build.yaml b/.forgejo/workflows/build.yaml
index e7f979e..faf0b24 100644
--- a/.forgejo/workflows/build.yaml
+++ b/.forgejo/workflows/build.yaml
@@ -40,7 +40,7 @@ jobs:
         shell: bash
         run: |
           set -o pipefail
-          DRVOUT=nix build .#deploy-json.${{ matrix.system }} --print-out-paths
+          DRVOUT=$(nix build .#deploy-json.${{ matrix.system }} --print-out-paths)
           echo "DRVOUT=$DRVOUT" >> $GITHUB_ENV
       - name: Push cache for ${{ matrix.name }} to cachix
         id: "push-to-cachix"