diff --git a/lib/ransack.rb b/lib/ransack.rb
index 180f76a..bbcd4e9 100644
--- a/lib/ransack.rb
+++ b/lib/ransack.rb
@@ -7,13 +7,6 @@ Ransack::Adapters.object_mapper.require_constants
 module Ransack
   extend Configuration
   class UntraversableAssociationError < StandardError; end;
-
-  SUPPORTS_ATTRIBUTE_ALIAS =
-  begin
-    ActiveRecord::Base.respond_to?(:attribute_aliases)
-  rescue NameError
-    false
-  end
 end
 
 Ransack.configure do |config|
diff --git a/lib/ransack/adapters/active_record.rb b/lib/ransack/adapters/active_record.rb
index 0ffbf30..03efdac 100644
--- a/lib/ransack/adapters/active_record.rb
+++ b/lib/ransack/adapters/active_record.rb
@@ -1,5 +1,15 @@
 require 'ransack/adapters/active_record/base'
-ActiveRecord::Base.extend Ransack::Adapters::ActiveRecord::Base
+
+ActiveSupport.on_load(:active_record) do
+  extend Ransack::Adapters::ActiveRecord::Base
+
+  Ransack::SUPPORTS_ATTRIBUTE_ALIAS =
+  begin
+    ActiveRecord::Base.respond_to?(:attribute_aliases)
+  rescue NameError
+    false
+  end
+end
 
 require 'ransack/adapters/active_record/context'