diff --git a/setup/inc/sql/b19dc97d-b16d6d60.patch.sql b/include/upgrader/patches/b19dc97d-435c62c3.patch.sql
similarity index 63%
rename from setup/inc/sql/b19dc97d-b16d6d60.patch.sql
rename to include/upgrader/patches/b19dc97d-435c62c3.patch.sql
index 2420917bfdfd50b1b75e778abc047aa25ccfe1de..b908348a728445778725b9215eebe432e270e9dc 100644
--- a/setup/inc/sql/b19dc97d-b16d6d60.patch.sql
+++ b/include/upgrader/patches/b19dc97d-435c62c3.patch.sql
@@ -8,6 +8,9 @@ ALTER TABLE `%TABLE_PREFIX%email_filter`
     ADD `canned_response_id` int(11) unsigned NOT NULL default '0'
         AFTER `disable_autoresponder`;
 
+-- Add index for linking responses to messages quickly
+ALTER TABLE `%TABLE_PREFIX%ticket_thread` ADD KEY `pid` (`pid`);
+
 -- Finished with patch
 UPDATE `%TABLE_PREFIX%config`
-    SET `schema_signature`='71e05961fdb7a993a21704ae513512bc';
+    SET `schema_signature`='435c62c3b23795529bcfae7e7371d82e';
diff --git a/main.inc.php b/main.inc.php
index 2721c554927315171c307e4d59693c3048a42789..1de9c91a3185d6a740cf9832069be71c0a29a805 100644
--- a/main.inc.php
+++ b/main.inc.php
@@ -63,7 +63,7 @@
 
     #Current version && schema signature (Changes from version to version)
     define('THIS_VERSION','1.7-DPR4'); //Shown on admin panel
-    define('SCHEMA_SIGNATURE','71e05961fdb7a993a21704ae513512bc'); //MD5 signature of the db schema. (used to trigger upgrades)
+    define('SCHEMA_SIGNATURE','435c62c3b23795529bcfae7e7371d82e'); //MD5 signature of the db schema. (used to trigger upgrades)
 
     #load config info
     $configfile='';
diff --git a/setup/inc/sql/osticket-v1.7-mysql.sql b/setup/inc/sql/osticket-v1.7-mysql.sql
index 9d3fa288eca45ccc2b53d445c2c52710f1ce0ce6..ed6ea688e34b1e00a2adb0cbebdfe22a02e6f3d1 100644
--- a/setup/inc/sql/osticket-v1.7-mysql.sql
+++ b/setup/inc/sql/osticket-v1.7-mysql.sql
@@ -660,6 +660,7 @@ CREATE TABLE `%TABLE_PREFIX%ticket_thread` (
   PRIMARY KEY  (`id`),
   KEY `ticket_id` (`ticket_id`),
   KEY `staff_id` (`staff_id`),
+  KEY `pid` (`pid`),
   FULLTEXT KEY `body` (`body`)
 ) ENGINE=MyISAM  DEFAULT CHARSET=utf8;
 
diff --git a/setup/inc/sql/osticket-v1.7-mysql.sql.md5 b/setup/inc/sql/osticket-v1.7-mysql.sql.md5
index 7363f25c71c7234c4ca996b2a378781e4cec297f..c3f03508703f6860c9628810c3b59ef8af0ce864 100644
--- a/setup/inc/sql/osticket-v1.7-mysql.sql.md5
+++ b/setup/inc/sql/osticket-v1.7-mysql.sql.md5
@@ -1 +1 @@
-b16d6d6021962e9e8674b6a81d9609bd
+435c62c3b23795529bcfae7e7371d82e