diff --git a/src/testdir/test_channel.vim b/src/testdir/test_channel.vim
index 3d9f6d0..76c7c4e 100644
--- a/src/testdir/test_channel.vim
+++ b/src/testdir/test_channel.vim
@@ -147,8 +147,8 @@
   " check setting options (without testing the effect)
   call ch_setoptions(handle, {'callback': 's:NotUsed'})
   call ch_setoptions(handle, {'timeout': 1111})
+  call ch_setoptions(handle, {'mode': 'json'})
   call assert_fails("call ch_setoptions(handle, {'waittime': 111})", "E475")
-  call assert_fails("call ch_setoptions(handle, {'mode': 'json'})", "E475")
   call ch_setoptions(handle, {'callback': ''})
 
   " Send an eval request that works.