diff --git a/src/testdir/test_user_func.vim b/src/testdir/test_user_func.vim
index aec3619..d4d149c 100644
--- a/src/testdir/test_user_func.vim
+++ b/src/testdir/test_user_func.vim
@@ -222,6 +222,17 @@
   delfunc Xtest
   set verbose=0
 
+  func Xtest(a1, a2)
+    echo a:a1 .. a:a2
+  endfunc
+  set verbose=15
+  redir @a
+  call Xtest(123, repeat('x', 100))
+  redir END
+  call assert_match('calling Xtest(123, ''xxxxxxx.*x\.\.\.x.*xxxx'')', getreg('a'))
+  delfunc Xtest
+  set verbose=0
+
   function Foo()
     echo 'hello'
   endfunction | echo 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'