diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 28cccf7..aa10497 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -26,6 +26,6 @@ jobs:
       - name: Check that the file is correctly uploaded
         run: |
           curl -s -o test-uploaded.txt ${{ steps.upload.outputs.url }}
-          diff test.txt test-uploaded.txt
+          nix shell "nixpkgs#diffutils" -c "diff test.txt test-uploaded.txt"
           rm test.txt