diff --git a/lib/bson/ordered_hash.rb b/lib/bson/ordered_hash.rb
index af82ecc..c523dab 100644
--- a/lib/bson/ordered_hash.rb
+++ b/lib/bson/ordered_hash.rb
@@ -159,20 +159,22 @@ module BSON
         @ordered_keys = []
       end
 
-      def hash
-        code = 17
-        each_pair do |key, value|
-          code = 37 * code + key.hash
-          code = 37 * code + value.hash
+      if RUBY_VERSION =~ /1.8.6/
+        def hash
+          code = 17
+          each_pair do |key, value|
+            code = 37 * code + key.hash
+            code = 37 * code + value.hash
+          end
+          code & 0x7fffffff
         end
-        code & 0x7fffffff
-      end
 
-      def eql?(o)
-        if o.instance_of? BSON::OrderedHash
-          self.hash == o.hash
-        else
-          false
+        def eql?(o)
+          if o.instance_of? BSON::OrderedHash
+            self.hash == o.hash
+          else
+            false
+          end
         end
       end
 
diff --git a/test/bson/ordered_hash_test.rb b/test/bson/ordered_hash_test.rb
index c837eb3..16e05ea 100644
--- a/test/bson/ordered_hash_test.rb
+++ b/test/bson/ordered_hash_test.rb
@@ -45,6 +45,23 @@ class OrderedHashTest < Test::Unit::TestCase
     assert_equal 1, list.uniq.size
   end
 
+  if !(RUBY_VERSION =~ /1.8.6/)
+    def test_compatibility_with_hash
+      list = []
+      doc  = BSON::OrderedHash.new
+      doc['_id']  = 'ab12'
+      doc['name'] = 'test'
+
+      doc2 = {}
+      doc2['_id']  = 'ab12'
+      doc2['name'] = 'test'
+      list << doc
+      list << doc2
+
+      assert_equal 1, list.uniq.size
+    end
+  end
+
   def test_equality
     a = BSON::OrderedHash.new
     a['x'] = 1