diff --git a/src/testdir/sautest/autoload/foo.vim b/src/testdir/sautest/autoload/foo.vim
index d7dcd5c..298e727 100644
--- a/src/testdir/sautest/autoload/foo.vim
+++ b/src/testdir/sautest/autoload/foo.vim
@@ -5,3 +5,7 @@
 func foo#bar.echo()
   let g:called_foo_bar_echo += 1
 endfunc
+
+func foo#addFoo(head)
+  return a:head .. 'foo'
+endfunc