diff --git a/src/testdir/test64.ok b/src/testdir/test64.ok
index 401da40..4bbc533 100644
--- a/src/testdir/test64.ok
+++ b/src/testdir/test64.ok
@@ -944,6 +944,9 @@
 OK 0 - \\\@<!\${\(\d\+\%(:.\{-}\)\?\\\@<!\)}
 OK 1 - \\\@<!\${\(\d\+\%(:.\{-}\)\?\\\@<!\)}
 OK 2 - \\\@<!\${\(\d\+\%(:.\{-}\)\?\\\@<!\)}
+OK 0 - ^\(a*\)\1$
+OK 1 - ^\(a*\)\1$
+OK 2 - ^\(a*\)\1$
 OK 0 - <\@<=span.
 OK 1 - <\@<=span.
 OK 2 - <\@<=span.