diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index f7f6e65..40b7809 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -291,6 +291,8 @@
   let lines =<< trim END
       call assert_equal('123', printf('123'))
 
+      call assert_equal('', printf('%'))
+      call assert_equal('', printf('%.0d', 0))
       call assert_equal('123', printf('%d', 123))
       call assert_equal('123', printf('%i', 123))
       call assert_equal('123', printf('%D', 123))