diff --git a/tests/test-patch-offset b/tests/test-patch-offset
--- a/tests/test-patch-offset
+++ b/tests/test-patch-offset
@@ -63,5 +63,5 @@ EOF
 
 echo % compare imported changes against reference file
 python ../writepatterns.py aref 34X 10A 1B 1a 9A 1C 10A 1B 10A 1D 10A 1B 1a 9A 1E 10A 1B 1a 9A
-diff -u aref a
+diff aref a