1 files changed, 14 insertions, 0 deletions
diff --git a/test/psych/test_hash.rb b/test/psych/test_hash.rb
index 3147076792..4bd4edfc8c 100644
--- a/test/psych/test_hash.rb
+++ b/test/psych/test_hash.rb
@@ -2,11 +2,25 @@ require 'psych/helper'
 
 module Psych
   class TestHash < TestCase
+    class X < Hash
+    end
+
     def setup
       super
       @hash = { :a => 'b' }
     end
 
+    def test_empty_subclass
+      assert_match "!ruby/hash:#{X}", Psych.dump(X.new)
+      x = Psych.load Psych.dump X.new
+      assert_equal X, x.class
+    end
+
+    def test_map
+      x = Psych.load "--- !map:#{X} { }\n"
+      assert_equal X, x.class
+    end
+
     def test_self_referential
       @hash['self'] = @hash
       assert_cycle(@hash)