fix.diff

diff --git a/test/namespaces/test_namespaces_in_merged_doc.rb b/test/namespaces/test_namespaces_in_merged_doc.rb
index fb7355d..d9b739c 100644
--- a/test/namespaces/test_namespaces_in_merged_doc.rb
+++ b/test/namespaces/test_namespaces_in_merged_doc.rb
@@ -21,7 +21,10 @@ module Nokogiri
         root  = @doc1.at("defs")
         toadd = @doc2.at("svg")
 
-        root.add_child(toadd.children)
+        text_node = @doc2.at("text")
+        toadd.children.each do |child|
+          root.add_child child.clone
+        end
 
         new_node = @doc1.at("text")
 
@@ -29,9 +32,9 @@ module Nokogiri
         assert_equal "http://www.w3.org/2000/svg", toadd.namespace.href
         assert_equal "http://www.w3.org/2000/svg", new_node.namespace.href
 
-        assert_equal nil, root.namespace.prefix
-        assert_equal nil, toadd.namespace.prefix
-        assert_equal nil, new_node.namespace.prefix #fails, returns "default"
+        assert_nil root.namespace.prefix
+        assert_nil toadd.namespace.prefix
+        assert_nil new_node.namespace.prefix #fails, returns "default"
       end
     end
   end