3 files changed, 6 insertions, 8 deletions
diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index 25d5d84ce6..24575438c0 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -255,11 +255,7 @@ module ActiveModel
 
       # Returns true if the attribute methods defined have been generated.
       def generated_attribute_methods #:nodoc:
-        @generated_attribute_methods ||= begin
-          mod = Module.new
-          include mod
-          mod
-        end
+        @generated_attribute_methods ||= Module.new.tap { |mod| include mod }
       end
 
       protected
diff --git a/activemodel/lib/active_model/serialization.rb b/activemodel/lib/active_model/serialization.rb
index 4403ef060b..00cd05b7ef 100644
--- a/activemodel/lib/active_model/serialization.rb
+++ b/activemodel/lib/active_model/serialization.rb
@@ -87,8 +87,8 @@ module ActiveModel
       Array(options[:methods]).each { |m| hash[m.to_s] = send(m) if respond_to?(m) }
 
       serializable_add_includes(options) do |association, records, opts|
-        hash[association.to_s] = if records.is_a?(Enumerable)
-          records.map { |a| a.serializable_hash(opts) }
+        hash[association.to_s] = if records.respond_to?(:to_ary)
+          records.to_ary.map { |a| a.serializable_hash(opts) }
         else
           records.serializable_hash(opts)
         end
diff --git a/activemodel/lib/active_model/serializers/xml.rb b/activemodel/lib/active_model/serializers/xml.rb
index 5084298210..b78f1ff3f3 100644
--- a/activemodel/lib/active_model/serializers/xml.rb
+++ b/activemodel/lib/active_model/serializers/xml.rb
@@ -115,7 +115,9 @@ module ActiveModel
           merged_options = opts.merge(options.slice(:builder, :indent))
           merged_options[:skip_instruct] = true
 
-          if records.is_a?(Enumerable)
+          if records.respond_to?(:to_ary)
+            records = records.to_ary
+
             tag  = ActiveSupport::XmlMini.rename_key(association.to_s, options)
             type = options[:skip_types] ? { } : {:type => "array"}
             association_name = association.to_s.singularize