--- lib/rack/auth/digest/params.rb.old  2009-12-18 20:42:09.000000000 +0100
+++ lib/rack/auth/digest/params.rb      2009-12-18 20:42:24.000000000 +0100
@@ -35,7 +35,7 @@
           super k.to_s, v.to_s
         end

-        UNQUOTED = ['qop', 'nc', 'stale']
+        UNQUOTED = ['nc', 'stale']

         def to_s
           inject([]) do |parts, (k, v)|