diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index 142455b..7d7870e 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -90,3 +90,14 @@
     call assert_true(0, 'should not get here')
   endfor
 endfunc
+
+func Test_compare_null_dict()
+  call assert_fails('let x = test_null_dict()[10]')
+  call assert_equal({}, {})
+  call assert_equal(test_null_dict(), test_null_dict())
+  call assert_notequal({}, test_null_dict())
+endfunc
+
+func Test_set_reg_null_list()
+  call setreg('x', test_null_list())
+endfunc