diff --git a/test/ruby/test_m17n.rb b/test/ruby/test_m17n.rb
index 2df7203227..5a0115e285 100644
--- a/test/ruby/test_m17n.rb
+++ b/test/ruby/test_m17n.rb
@@ -890,6 +890,9 @@ class TestM17N < Test::Unit::TestCase
   end
 
   def test_marshal
+    s1 = "\xa1\xa1".force_encoding("euc-jp")
+    s2 = Marshal.load(Marshal.dump(s1))
+    assert_equal(s1, s2)
   end
 
   def test_env
@@ -898,4 +901,10 @@ class TestM17N < Test::Unit::TestCase
       assert_equal(Encoding::ASCII_8BIT, v.encoding)
     }
   end
+
+  def test_encoding_find
+    assert_raise(ArgumentError) {
+      Encoding.find("utf-8".force_encoding("utf-16be"))
+    }
+  end
 end