diff --git a/lib/generators/unread/polymorphic_reader_migration/polymorphic_reader_migration_generator.rb b/lib/generators/unread/polymorphic_reader_migration/polymorphic_reader_migration_generator.rb
index 05e0f2d..b865ac6 100644
--- a/lib/generators/unread/polymorphic_reader_migration/polymorphic_reader_migration_generator.rb
+++ b/lib/generators/unread/polymorphic_reader_migration/polymorphic_reader_migration_generator.rb
@@ -13,11 +13,22 @@ def create_migration_file
     end
 
     def self.next_migration_number(dirname)
-      if ActiveRecord::Base.timestamped_migrations
-        Time.now.utc.strftime("%Y%m%d%H%M%S")
+      if self.timestamped_migrations?
+        Time.now.utc.strftime('%Y%m%d%H%M%S')
       else
         "%.3d" % (current_migration_number(dirname) + 1)
       end
     end
+
+    def self.timestamped_migrations?
+      (
+        ActiveRecord::Base.respond_to?(:timestamped_migrations) &&
+          ActiveRecord::Base.timestamped_migrations
+      ) ||
+        (
+          ActiveRecord.respond_to?(:timestamped_migrations) &&
+            ActiveRecord.timestamped_migrations
+        )
+    end
   end
 end