Hello, I started poking at the URI specs to see what I could get working. The attached patch was required to make the specs run (URI provides 11 arguments to initialize). I then started taking a look at why the equality spec fails and have tracked it back to the dup call not returning the same values in the duplicate object. This can be seen by doing a self.to_s and uri.to_s in the normalize function of lib/uri/generic.rb. self.to_s -> http://example.com/#fragMENT uri.to_s -> http://example.com/ For some reason, the fragment instance variable is being dropped from the duplicated object while all of the other instance variables are being copied over. You can see the same behaviour with the following script ------------ class Foo def initialize(a, b, c, d, e, f, g, h, i, j, k) @a = a @b = b @c = c @d = d @e = e @f = f @g = g @h = h @i = i @j = j @k = k end def to_s "#{@a} #{@b} #{@c} #{@d} #{@e} #{@f} #{@g} #{@h} #{@i} #{@j} #{@k}" end end f = Foo.new("a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k") g = f.dup puts f.to_s puts g.to_s ----------- titania:test dj2$ macruby ./dup.rb a b c d e f g h i j k a b c d e f g h i j false dan