diff --git a/tests/test-help.out b/tests/test-help.out
--- a/tests/test-help.out
+++ b/tests/test-help.out
@@ -129,7 +129,7 @@ options:
 
  -I --include  include path in search
  -X --exclude  exclude path from search
-hg diff [-I] [-X] [-r REV1 [-r REV2]] [FILE]...
+hg diff [-a] [-I] [-X] [-r REV1 [-r REV2]] [FILE]...
 
 diff working directory (or selected files)