diff --git a/railties/lib/rails/generators/generated_attribute.rb b/railties/lib/rails/generators/generated_attribute.rb
index 50e7aa85acf84ea876158769d378f421c7711ac3..25d0161e4c0fe4a84c7b46244351bc736d2fb5e5 100644
--- a/railties/lib/rails/generators/generated_attribute.rb
+++ b/railties/lib/rails/generators/generated_attribute.rb
@@ -1,6 +1,4 @@
 require 'active_support/time'
-require 'active_support/core_ext/object/inclusion'
-require 'active_support/core_ext/object/blank'
 
 module Rails
   module Generators
@@ -21,15 +19,20 @@ def parse(column_definition)
           has_index, type = type, nil if INDEX_OPTIONS.include?(type)
 
           type, attr_options = *parse_type_and_options(type)
+          type = type.to_sym if type
 
-          if type.in?(%w(references belongs_to))
-            references_index = UNIQ_INDEX_OPTIONS.include?(has_index) ? {:unique => true} : true
-            attr_options.merge!({:index => references_index})
+          if type && reference?(type)
+            references_index = UNIQ_INDEX_OPTIONS.include?(has_index) ? { :unique => true } : true
+            attr_options[:index] = references_index
           end
 
           new(name, type, has_index, attr_options)
         end
 
+        def reference?(type)
+          [:references, :belongs_to].include? type
+        end
+
         private
 
         # parse possible attribute options like :limit for string/text/binary/integer or :precision/:scale for decimals
@@ -48,7 +51,7 @@ def parse_type_and_options(type)
 
       def initialize(name, type=nil, index_type=false, attr_options={})
         @name           = name
-        @type           = (type.presence || :string).to_sym
+        @type           = type || :string
         @has_index      = INDEX_OPTIONS.include?(index_type)
         @has_uniq_index = UNIQ_INDEX_OPTIONS.include?(index_type)
         @attr_options   = attr_options
@@ -93,7 +96,7 @@ def index_name
       end
 
       def reference?
-        self.type.in?(:references, :belongs_to)
+        self.class.reference?(type)
       end
 
       def has_index?