1 files changed, 16 insertions, 0 deletions
diff --git a/test/psych/test_encoding.rb b/test/psych/test_encoding.rb
index 029ff75ed9..a341c47859 100644
--- a/test/psych/test_encoding.rb
+++ b/test/psych/test_encoding.rb
@@ -40,6 +40,22 @@ module Psych
       assert_match(/alias value/, e.message)
     end
 
+    def test_to_yaml_is_valid
+      ext_before = Encoding.default_external
+      int_before = Encoding.default_internal
+
+      Encoding.default_external = Encoding::US_ASCII
+      Encoding.default_internal = nil
+
+      s = "こんにちは！"
+      # If no encoding is specified, use UTF-8
+      assert_equal Encoding::UTF_8, Psych.dump(s).encoding
+      assert_equal s, Psych.load(Psych.dump(s))
+    ensure
+      Encoding.default_external = ext_before
+      Encoding.default_internal = int_before
+    end
+
     def test_start_mapping
       foo = 'foo'
       bar = 'バー'