diff --git a/testsuite/tail/tail-works b/testsuite/tail/tail-works
index 321db7f..27a905f 100644
--- a/testsuite/tail/tail-works
+++ b/testsuite/tail/tail-works
@@ -1,3 +1,4 @@
-tail -n 2 ../README > logfile.gnu
-busybox tail -n 2 ../README > logfile.bb
+[ -n "$d" ] || d=..
+tail -n 2 "$d/README" > logfile.gnu
+busybox tail -n 2 "$d/README" > logfile.bb
 cmp logfile.gnu logfile.bb