diff --git a/db/migrate/20140530155538_create_active_admin_comments.rb b/db/migrate/20140530155538_create_active_admin_comments.rb
index 9efd147..81e0af7 100644
--- a/db/migrate/20140530155538_create_active_admin_comments.rb
+++ b/db/migrate/20140530155538_create_active_admin_comments.rb
@@ -1,8 +1,8 @@
 class CreateActiveAdminComments < ActiveRecord::Migration
   def self.up
     create_table :active_admin_comments do |t|
-      t.string :namespace
-      t.text   :body
+      t.string :namespace, null:false
+      t.text   :body, null:false
       t.string :resource_id,   null: false
       t.string :resource_type, null: false
       t.references :author, polymorphic: true