diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index a7ad65e..7681125 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -237,6 +237,7 @@
   call assert_equal(1, OneByRef())
   let OneByRef = funcref('One')
   call assert_equal(2, OneByRef())
+  call assert_fails('echo funcref("{")', 'E475:')
 endfunc
 
 func Test_setmatches()