diff --git a/database/2.4_to_3.0.sql b/database/2.4_to_3.0.sql
index 2652ed369..09761d89a 100644
--- a/database/2.4_to_3.0.sql
+++ b/database/2.4_to_3.0.sql
@@ -37,6 +37,9 @@ ALTER TABLE `ospos_items_taxes`
 ALTER TABLE `ospos_customers`
  ADD COLUMN `discount_percent` decimal(15,2) NOT NULL DEFAULT '0.00';
 
+ 
+-- alter config table
+
 UPDATE `ospos_app_config` SET `key` = 'receipt_show_total_discount' WHERE `key` = 'show_total_discount';
  
 INSERT INTO `ospos_app_config` (`key`, `value`) VALUES
@@ -56,6 +59,9 @@ INSERT INTO `ospos_app_config` (`key`, `value`) VALUES
  
 DELETE FROM `ospos_app_config` WHERE `key` = 'use_invoice_template';
 
+
+-- add messages (SMS) module and permissions
+
 UPDATE `ospos_modules` SET `sort` = 110 WHERE `name_lang_key` = 'module_config';
 
 INSERT INTO `ospos_modules` (`name_lang_key`, `desc_lang_key`, `sort`, `module_id`) VALUES
@@ -67,6 +73,16 @@ INSERT INTO `ospos_permissions` (`permission_id`, `module_id`) VALUES
 INSERT INTO `ospos_grants` (`permission_id`, `person_id`) VALUES
  ('messages', 1);
 
-ALTER TABLE `ospos_sessions`
-   DROP PRIMARY KEY;
+
+-- alter sessions table
+
+DROP TABLE `ospos_sessions`;
+
+CREATE TABLE `ospos_sessions` (
+  `id` varchar(40) NOT NULL,
+  `ip_address` varchar(45) NOT NULL,
+  `timestamp` int(10) unsigned DEFAULT 0 NOT NULL,
+  `data` blob NOT NULL,
+  KEY `ci_sessions_timestamp` (`timestamp`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
  
\ No newline at end of file
diff --git a/database/database.sql b/database/database.sql
index 2012108f0..5b55f083f 100644
--- a/database/database.sql
+++ b/database/database.sql
@@ -676,10 +676,11 @@ CREATE TABLE `ospos_sales_suspended_payments` (
 --
 
 CREATE TABLE `ospos_sessions` (
-  `id` varchar(40) NOT NULL DEFAULT '0',
-  `ip_address` varchar(45) NOT NULL DEFAULT '0',
+  `id` varchar(40) NOT NULL,
+  `ip_address` varchar(45) NOT NULL,
+  `timestamp` int(10) unsigned DEFAULT 0 NOT NULL,
   `data` blob NOT NULL,
-  `timestamp` int(10) unsigned NOT NULL DEFAULT '0'
+  KEY `ci_sessions_timestamp` (`timestamp`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
 --
diff --git a/database/migrate_phppos_dist.sql b/database/migrate_phppos_dist.sql
index ac3657827..a21821db4 100644
--- a/database/migrate_phppos_dist.sql
+++ b/database/migrate_phppos_dist.sql
@@ -676,10 +676,11 @@ CREATE TABLE `ospos_sales_suspended_payments` (
 --
 
 CREATE TABLE `ospos_sessions` (
-  `id` varchar(40) NOT NULL DEFAULT '0',
-  `ip_address` varchar(45) NOT NULL DEFAULT '0',
+  `id` varchar(40) NOT NULL,
+  `ip_address` varchar(45) NOT NULL,
+  `timestamp` int(10) unsigned DEFAULT 0 NOT NULL,
   `data` blob NOT NULL,
-  `timestamp` int(10) unsigned NOT NULL DEFAULT '0'
+  KEY `ci_sessions_timestamp` (`timestamp`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
 --
diff --git a/database/tables.sql b/database/tables.sql
index 0e02835c3..afdac72d5 100644
--- a/database/tables.sql
+++ b/database/tables.sql
@@ -676,10 +676,11 @@ CREATE TABLE `ospos_sales_suspended_payments` (
 --
 
 CREATE TABLE `ospos_sessions` (
-  `id` varchar(40) NOT NULL DEFAULT '0',
-  `ip_address` varchar(45) NOT NULL DEFAULT '0',
+  `id` varchar(40) NOT NULL,
+  `ip_address` varchar(45) NOT NULL,
+  `timestamp` int(10) unsigned DEFAULT 0 NOT NULL,
   `data` blob NOT NULL,
-  `timestamp` int(10) unsigned NOT NULL DEFAULT '0'
+  KEY `ci_sessions_timestamp` (`timestamp`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
 --