diff --git a/sql/000_base_structure.sql b/sql/000_base_structure.sql
index 63f57241..8a80ee2e 100644
--- a/sql/000_base_structure.sql
+++ b/sql/000_base_structure.sql
@@ -155,8 +155,8 @@ CREATE TABLE IF NOT EXISTS `shares` (
 ) ENGINE=InnoDB  DEFAULT CHARSET=utf8;
 
 CREATE TABLE IF NOT EXISTS `shares_archive` (
-  `id` bigint(30) NOT NULL AUTO_INCREMENT,
-  `share_id` bigint(30) NOT NULL,
+  `id` bigint(30) unsigned NOT NULL AUTO_INCREMENT,
+  `share_id` bigint(30) unsigned NOT NULL,
   `username` varchar(120) NOT NULL,
   `our_result` enum('Y','N') DEFAULT NULL,
   `upstream_result` enum('Y','N') DEFAULT NULL,
diff --git a/upgrade/definitions/0.0.10_to_0.0.11.inc.php b/upgrade/definitions/0.0.10_to_0.0.11.inc.php
index 7f332dac..752b41a4 100644
--- a/upgrade/definitions/0.0.10_to_0.0.11.inc.php
+++ b/upgrade/definitions/0.0.10_to_0.0.11.inc.php
@@ -9,8 +9,8 @@ function run_0011() {
   $db_version_now = $setting->getValue('DB_VERSION');  // Our actual version installed
 
   // Upgrade specific variables
-  $aSql[] = "ALTER TABLE `shares_archive` MODIFY `id` bigint(30)";
-  $aSql[] = "ALTER TABLE `shares_archive` MODIFY `share_id` bigint(30)";
+  $aSql[] = "ALTER TABLE `shares_archive` CHANGE  `id` `id` BIGINT(30) unsigned NOT NULL AUTO_INCREMENT";
+  $aSql[] = "ALTER TABLE `shares_archive` CHANGE `share_id` `share_id` BIGINT(30) unsigned NOT NULL";
   $aSql[] = "UPDATE " . $setting->getTableName() . "    SET value = '0.0.11' WHERE name = 'DB_VERSION'";
 
   if ($db_version_now == $db_version_old && version_compare($db_version_now, DB_VERSION, '<')) {
@@ -28,4 +28,4 @@ function run_0011() {
     }
   }
 }
-?>
+?>
\ No newline at end of file