diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index f55e846..38cd793 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -40,6 +40,9 @@
   " Will we ever have patch 9999?
   let ver = 'patch-' .. v:version / 100 .. '.' .. v:version % 100 .. '.9999'
   call assert_equal(0, has(ver))
+
+  " There actually isn't a patch 9.0.0, but this is more consistent.
+  call assert_equal(1, has('patch-9.0.0'))
 endfunc
 
 func Test_empty()