diff --git a/lib/shoulda/matchers/active_model/allow_mass_assignment_of_matcher.rb b/lib/shoulda/matchers/active_model/allow_mass_assignment_of_matcher.rb
index 3aab75f0..c642c178 100644
--- a/lib/shoulda/matchers/active_model/allow_mass_assignment_of_matcher.rb
+++ b/lib/shoulda/matchers/active_model/allow_mass_assignment_of_matcher.rb
@@ -20,19 +20,19 @@ module Shoulda # :nodoc:
 
         def initialize(attribute)
           @attribute = attribute.to_s
+          @options = {}
         end
 
         def as(role)
-          unless at_least_rails_3_1?
+          if less_than_active_model_3_1?
             raise "You can specify role only in Rails 3.1 or greater" 
           end
-          @role = role
+          @options[:role] = role
           self
         end
 
         def matches?(subject)
           @subject = subject
-          @role ||= :default
           if attr_mass_assignable?
             if whitelisting?
               @negative_failure_message = "#{@attribute} was made accessible"
@@ -62,6 +62,10 @@ module Shoulda # :nodoc:
 
         private
 
+        def role
+          @options[:role] || :default
+        end
+
         def protected_attributes
           @protected_attributes ||= (@subject.class.protected_attributes || [])
         end
@@ -79,10 +83,10 @@ module Shoulda # :nodoc:
         end
 
         def authorizer
-          if at_least_rails_3_1?
-            @subject.class.active_authorizer[@role]
-          else
+          if less_than_active_model_3_1?
             @subject.class.active_authorizer
+          else
+            @subject.class.active_authorizer[role]
           end
         end
 
@@ -90,8 +94,8 @@ module Shoulda # :nodoc:
           @subject.class.name
         end
 
-        def at_least_rails_3_1?
-          ::ActiveModel::VERSION::MAJOR == 3 && ::ActiveModel::VERSION::MINOR >= 1
+        def less_than_active_model_3_1?
+          ! (::ActiveModel::VERSION::MAJOR == 3 && ::ActiveModel::VERSION::MINOR >= 1)
         end
       end
     end
diff --git a/lib/shoulda/matchers/active_record/serialize_matcher.rb b/lib/shoulda/matchers/active_record/serialize_matcher.rb
index 4936dc03..02ee2bd0 100644
--- a/lib/shoulda/matchers/active_record/serialize_matcher.rb
+++ b/lib/shoulda/matchers/active_record/serialize_matcher.rb
@@ -18,15 +18,16 @@ module Shoulda # :nodoc:
       class SerializeMatcher # :nodoc:
         def initialize(name)
           @name = name.to_s
+          @options = {}
         end
 
         def as(type)
-          @type = type
+          @options[:type] = type
           self
         end
 
         def as_instance_of(type)
-          @instance_type = type
+          @options[:instance_type] = type
           self
         end
 
@@ -45,7 +46,7 @@ module Shoulda # :nodoc:
 
         def description
           description = "serialize :#{@name}"
-          description += " class_name => #{@type}" if @type
+          description += " class_name => #{@options[:type]}" if @options.key?(:type)
           description
         end
 
@@ -61,15 +62,15 @@ module Shoulda # :nodoc:
         end
 
         def class_valid?
-          if @type
+          if @options[:type]
             klass = model_class.serialized_attributes[@name]
-            if klass == @type
+            if klass == @options[:type]
               true
             else
-              if klass.respond_to?(:object_class) && klass.object_class == @type
+              if klass.respond_to?(:object_class) && klass.object_class == @options[:type]
                 true
               else
-                @missing = ":#{@name} should be a type of #{@type}"
+                @missing = ":#{@name} should be a type of #{@options[:type]}"
                 false
               end
             end
@@ -83,11 +84,11 @@ module Shoulda # :nodoc:
         end
 
         def instance_class_valid?
-          if @instance_type
-            if model_class.serialized_attributes[@name].class == @instance_type
+          if @options.key?(:instance_type)
+            if model_class.serialized_attributes[@name].class == @options[:instance_type]
               true
             else
-              @missing = ":#{@name} should be an instance of #{@type}"
+              @missing = ":#{@name} should be an instance of #{@options[:type]}"
               false
             end
           else
@@ -101,8 +102,8 @@ module Shoulda # :nodoc:
 
         def expectation
           expectation = "#{model_class.name} to serialize the attribute called :#{@name}"
-          expectation += " with a type of #{@type}" if @type
-          expectation += " with an instance of #{@instance_type}" if @instance_type
+          expectation += " with a type of #{@options[:type]}" if @options[:type]
+          expectation += " with an instance of #{@options[:instance_type]}" if @options[:instance_type]
           expectation
         end
       end