diff --git a/.github/workflows/build-deb.yaml b/.github/workflows/build-deb.yaml
index 5027f407c..b0bbc262f 100644
--- a/.github/workflows/build-deb.yaml
+++ b/.github/workflows/build-deb.yaml
@@ -55,7 +55,7 @@ jobs:
   check-modified-files:
     runs-on: ubuntu-latest
     outputs:
-      modified-files: ${{ toJSON(steps.git-diff.outputs.modified_files_json) }}
+      modified-files: ${{ toJSON(steps.git-diff.outputs.modified_files) }}
     steps:
       - run: |
           # foo