diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index 253cd49..eb51cd6 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -496,6 +496,8 @@
   let OneByRef = 'One'->funcref()
   call assert_equal(2, OneByRef())
   call assert_fails('echo funcref("{")', 'E475:')
+  let OneByRef = funcref("One", repeat(["foo"], 20))
+  call assert_fails('let OneByRef = funcref("One", repeat(["foo"], 21))', 'E118:')
 endfunc
 
 func Test_setmatches()