diff --git a/src/testdir/test_expand_func.vim b/src/testdir/test_expand_func.vim
index 3c430e1..59156af 100644
--- a/src/testdir/test_expand_func.vim
+++ b/src/testdir/test_expand_func.vim
@@ -82,10 +82,14 @@
 
 func Test_expand()
   new
-  call assert_equal("",  expand('%:S'))
+  call assert_equal("''", expand('%:S'))
   call assert_equal('3', '<slnum>'->expand())
   call assert_equal(['4'], expand('<slnum>', v:false, v:true))
   " Don't add any line above this, otherwise <slnum> will change.
+  call assert_equal("", expand('%'))
+  set verbose=1
+  call assert_equal("", expand('%'))
+  set verbose=0
   quit
 endfunc