3 files changed, 9 insertions, 11 deletions
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index fc8034f9c7..1b46727351 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -251,11 +251,9 @@ module ActiveModel
     #   person.errors.to_hash(true) # => {:name=>["name cannot be nil"]}
     def to_hash(full_messages = false)
       if full_messages
-        messages = {}
-        self.messages.each do |attribute, array|
+        self.messages.each_with_object({}) do |(attribute, array), messages|
           messages[attribute] = array.map { |message| full_message(attribute, message) }
         end
-        messages
       else
         self.messages.dup
       end
diff --git a/activemodel/lib/active_model/model.rb b/activemodel/lib/active_model/model.rb
index 640024eaa1..d51d6ddcc9 100644
--- a/activemodel/lib/active_model/model.rb
+++ b/activemodel/lib/active_model/model.rb
@@ -56,13 +56,13 @@ module ActiveModel
   # refer to the specific modules included in <tt>ActiveModel::Model</tt>
   # (see below).
   module Model
-    def self.included(base) #:nodoc:
-      base.class_eval do
-        extend  ActiveModel::Naming
-        extend  ActiveModel::Translation
-        include ActiveModel::Validations
-        include ActiveModel::Conversion
-      end
+    extend ActiveSupport::Concern
+    include ActiveModel::Validations
+    include ActiveModel::Conversion
+
+    included do
+      extend ActiveModel::Naming
+      extend ActiveModel::Translation
     end
 
     # Initializes a new model with the given +params+.
diff --git a/activemodel/lib/active_model/validations/confirmation.rb b/activemodel/lib/active_model/validations/confirmation.rb
index a51523912f..1b11c28087 100644
--- a/activemodel/lib/active_model/validations/confirmation.rb
+++ b/activemodel/lib/active_model/validations/confirmation.rb
@@ -54,7 +54,7 @@ module ActiveModel
       #
       # Configuration options:
       # * <tt>:message</tt> - A custom error message (default is: "doesn't match
-      #   confirmation").
+      #   <tt>%{translated_attribute_name}</tt>").
       #
       # There is also a list of default options supported by every validator:
       # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.