3 files changed, 25 insertions, 12 deletions
diff --git a/activesupport/lib/active_support/autoload.rb b/activesupport/lib/active_support/autoload.rb
index ed229d1c5f..75706855d6 100644
--- a/activesupport/lib/active_support/autoload.rb
+++ b/activesupport/lib/active_support/autoload.rb
@@ -5,7 +5,7 @@ module ActiveSupport
   autoload :BufferedLogger, 'active_support/buffered_logger'
   autoload :Cache, 'active_support/cache'
   autoload :Callbacks, 'active_support/callbacks'
-  autoload :NewCallbacks, 'active_support/new_callbacks'
+  autoload :Concern, 'active_support/concern'
   autoload :ConcurrentHash, 'active_support/concurrent_hash'
   autoload :DependencyModule, 'active_support/dependency_module'
   autoload :Deprecation, 'active_support/deprecation'
@@ -15,6 +15,7 @@ module ActiveSupport
   autoload :MessageEncryptor, 'active_support/message_encryptor'
   autoload :MessageVerifier, 'active_support/message_verifier'
   autoload :Multibyte, 'active_support/multibyte'
+  autoload :NewCallbacks, 'active_support/new_callbacks'
   autoload :OptionMerger, 'active_support/option_merger'
   autoload :OrderedHash, 'active_support/ordered_hash'
   autoload :OrderedOptions, 'active_support/ordered_options'
diff --git a/activesupport/lib/active_support/concern.rb b/activesupport/lib/active_support/concern.rb
new file mode 100644
index 0000000000..154f8807f7
--- /dev/null
+++ b/activesupport/lib/active_support/concern.rb
@@ -0,0 +1,22 @@
+require 'active_support/dependency_module'
+
+module ActiveSupport
+  module Concern
+    include DependencyModule
+
+    def append_features(base)
+      if super
+        base.extend const_get("ClassMethods") if const_defined?("ClassMethods")
+        base.class_eval(&@_included_block) if instance_variable_defined?("@_included_block")
+      end
+    end
+
+    def included(base = nil, &block)
+      if base.nil?
+        @_included_block = block
+      else
+        super
+      end
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/dependency_module.rb b/activesupport/lib/active_support/dependency_module.rb
index 9872b9654b..6847c0f86a 100644
--- a/activesupport/lib/active_support/dependency_module.rb
+++ b/activesupport/lib/active_support/dependency_module.rb
@@ -1,19 +1,9 @@
 module ActiveSupport
   module DependencyModule
     def append_features(base)
-      return if base < self
+      return false if base < self
       (@_dependencies ||= []).each { |dep| base.send(:include, dep) }
       super
-      base.extend const_get("ClassMethods") if const_defined?("ClassMethods")
-      base.class_eval(&@_included_block) if instance_variable_defined?("@_included_block")
-    end
-
-    def included(base = nil, &block)
-      if base.nil?
-        @_included_block = block
-      else
-        super
-      end
     end
 
     def depends_on(*mods)