diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index f5c9e26..33115c7 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -36,3 +36,17 @@
   call assert_false(has('patch-9.1.0'))
   call assert_false(has('patch-9.9.1'))
 endfunc
+
+func Test_dict()
+  let d = {'': 'empty', 'a': 'a', 0: 'zero'}
+  call assert_equal('empty', d[''])
+  call assert_equal('a', d['a'])
+  call assert_equal('zero', d[0])
+  call assert_true(has_key(d, ''))
+  call assert_true(has_key(d, 'a'))
+
+  let d[''] = 'none'
+  let d['a'] = 'aaa'
+  call assert_equal('none', d[''])
+  call assert_equal('aaa', d['a'])
+endfunc