diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 750c4a2..e5d56ac 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -1749,7 +1749,8 @@
   call assert_equal(2, count("fooooo", "oo"))
   call assert_equal(0, count("foo", ""))
 
-  call assert_fails('call count(0, 0)', 'E712:')
+  call assert_fails('call count(0, 0)', 'E706:')
+  call assert_fails('call count("", "", {})', ['E728:', 'E728:'])
 endfunc
 
 func Test_changenr()