diff --git a/activemodel/lib/active_model.rb b/activemodel/lib/active_model.rb
index eed74731fa..0665cfbae5 100644
--- a/activemodel/lib/active_model.rb
+++ b/activemodel/lib/active_model.rb
@@ -27,7 +27,6 @@ require 'active_support'
 
 module ActiveModel
   autoload :APICompliant, 'active_model/api_compliant'
-  autoload :Base, 'active_model/base'
   autoload :DeprecatedErrorMethods, 'active_model/deprecated_error_methods'
   autoload :Errors, 'active_model/errors'
   autoload :Name, 'active_model/naming'
diff --git a/activemodel/lib/active_model/base.rb b/activemodel/lib/active_model/base.rb
deleted file mode 100644
index a500adfdf1..0000000000
--- a/activemodel/lib/active_model/base.rb
+++ /dev/null
@@ -1,8 +0,0 @@
-module ActiveModel
-  class Base
-    include Observing
-    # disabled, until they're tested
-    # include Callbacks
-    # include Validations
-  end
-end
\ No newline at end of file
diff --git a/activemodel/test/cases/observing_test.rb b/activemodel/test/cases/observing_test.rb
index 564451fa2f..fbf93c19ef 100644
--- a/activemodel/test/cases/observing_test.rb
+++ b/activemodel/test/cases/observing_test.rb
@@ -1,6 +1,8 @@
 require 'cases/helper'
 
-class ObservedModel < ActiveModel::Base
+class ObservedModel
+  include ActiveModel::Observing
+
   class Observer
   end
 end
@@ -17,7 +19,8 @@ class FooObserver < ActiveModel::Observer
   end
 end
 
-class Foo < ActiveModel::Base
+class Foo
+  include ActiveModel::Observing
 end
 
 class ObservingTest < ActiveModel::TestCase