diff --git a/lib/generators/shortener/shortener_generator.rb b/lib/generators/shortener/shortener_generator.rb
index d6faff3..bab8377 100644
--- a/lib/generators/shortener/shortener_generator.rb
+++ b/lib/generators/shortener/shortener_generator.rb
@@ -9,7 +9,7 @@ def self.source_root
   end
 
   def self.next_migration_number(dirname)
-    if ActiveRecord::Base.timestamped_migrations
+    if ActiveRecord.timestamped_migrations
       Time.new.utc.strftime("%Y%m%d%H%M%S")
     else
       "%.3d" % (current_migration_number(dirname) + 1)