diff --git a/lib/make-system-tarball.sh b/lib/make-system-tarball.sh
index 5465c3497aa5..aadd0f6428c8 100644
--- a/lib/make-system-tarball.sh
+++ b/lib/make-system-tarball.sh
@@ -54,3 +54,5 @@ tar cvJf $out/tarball/$fileName.tar.xz *
 
 ensureDir $out/nix-support
 echo $system > $out/nix-support/system
+echo "file system-tarball $out/tarball/$fileName.tar.xz" > $out/nix-support/hydra-build-products
+