diff --git a/lib/acts_as_follower.rb b/lib/acts_as_follower.rb
index 040db64..c9246b2 100644
--- a/lib/acts_as_follower.rb
+++ b/lib/acts_as_follower.rb
@@ -6,28 +6,5 @@ module ActsAsFollower
   autoload :FollowerLib,  'acts_as_follower/follower_lib'
   autoload :FollowScopes, 'acts_as_follower/follow_scopes'
 
-  def self.setup
-    @configuration ||= Configuration.new
-    yield @configuration if block_given?
-  end
-
-  def self.method_missing(method_name, *args, &block)
-    if method_name == :custom_parent_classes=
-      ActiveSupport::Deprecation.warn("Setting custom parent classes is deprecated and will be removed in future versions.")
-    end
-    @configuration.respond_to?(method_name) ?
-        @configuration.send(method_name, *args, &block) : super
-  end
-
-  class Configuration
-    attr_accessor :custom_parent_classes
-
-    def initialize
-      @custom_parent_classes = []
-    end
-  end
-
-  setup
-
   require 'acts_as_follower/railtie' if defined?(Rails) && Rails::VERSION::MAJOR >= 3
 end
diff --git a/lib/acts_as_follower/follower_lib.rb b/lib/acts_as_follower/follower_lib.rb
index fa40023..57c1a90 100644
--- a/lib/acts_as_follower/follower_lib.rb
+++ b/lib/acts_as_follower/follower_lib.rb
@@ -3,14 +3,9 @@ module FollowerLib
 
     private
 
-    DEFAULT_PARENTS = [ApplicationRecord, ActiveRecord::Base]
-
     # Retrieves the parent class name if using STI.
     def parent_class_name(obj)
-      unless parent_classes.include?(obj.class.superclass)
-        return obj.class.base_class.name
-      end
-      obj.class.name
+      obj.class.base_class.name
     end
 
     def apply_options_to_scope(scope, options = {})
@@ -32,11 +27,5 @@ def apply_options_to_scope(scope, options = {})
       scope
     end
 
-    def parent_classes
-      return DEFAULT_PARENTS unless ActsAsFollower.custom_parent_classes
-
-      ActiveSupport::Deprecation.warn("Setting custom parent classes is deprecated and will be removed in future versions.")
-      ActsAsFollower.custom_parent_classes + DEFAULT_PARENTS
-    end
   end
 end
diff --git a/test/factories/somes.rb b/test/factories/somes.rb
deleted file mode 100644
index ce94210..0000000
--- a/test/factories/somes.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-FactoryGirl.define do
-  factory :daddy, :class => Some do |b|
-    b.name 'Daddy'
-  end
-
-  factory :mommy, :class => Some do |b|
-    b.name 'Mommy'
-  end
-end
diff --git a/test/follow_test.rb b/test/follow_test.rb
index b11cfe7..2f99749 100644
--- a/test/follow_test.rb
+++ b/test/follow_test.rb
@@ -7,22 +7,4 @@ def test_assert_true_should_be_true
     assert true
   end
 
-  context "configuration with setters" do
-    should "contain custom parents" do
-      ActsAsFollower.custom_parent_classes = [CustomRecord]
-
-      assert_equal [CustomRecord], ActsAsFollower.custom_parent_classes
-    end
-  end
-
-  context "#setup" do
-    should "contain custom parents via setup" do
-      ActsAsFollower.setup do |c|
-        c.custom_parent_classes = [CustomRecord]
-      end
-
-      assert_equal [CustomRecord], ActsAsFollower.custom_parent_classes
-    end
-  end
-
 end