diff --git a/phpBB/develop/create_schema_files.php b/phpBB/develop/create_schema_files.php
index 52c72fc72c..d7173f6f1f 100644
--- a/phpBB/develop/create_schema_files.php
+++ b/phpBB/develop/create_schema_files.php
@@ -1195,6 +1195,7 @@ function get_schema_struct()
 		'PRIMARY_KEY'	=> 'log_id',
 		'KEYS'			=> array(
 			'log_type'				=> array('INDEX', 'log_type'),
+			'log_time'				=> array('INDEX', 'log_time'),
 			'forum_id'				=> array('INDEX', 'forum_id'),
 			'topic_id'				=> array('INDEX', 'topic_id'),
 			'reportee_id'			=> array('INDEX', 'reportee_id'),
diff --git a/phpBB/develop/mysql_upgrader.php b/phpBB/develop/mysql_upgrader.php
index 77341500e1..22406d1286 100644
--- a/phpBB/develop/mysql_upgrader.php
+++ b/phpBB/develop/mysql_upgrader.php
@@ -667,6 +667,7 @@ function get_schema_struct()
 		'PRIMARY_KEY'	=> 'log_id',
 		'KEYS'			=> array(
 			'log_type'				=> array('INDEX', 'log_type'),
+			'log_time'				=> array('INDEX', 'log_time'),
 			'forum_id'				=> array('INDEX', 'forum_id'),
 			'topic_id'				=> array('INDEX', 'topic_id'),
 			'reportee_id'			=> array('INDEX', 'reportee_id'),
diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index 59ae95d0b4..952304b836 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -96,6 +96,7 @@
 		<li>[Fix] Various XHTML mistakes in prosilver and subsilver2. (Bugs #38555, #45505 - Patch by Raimon, #45785, #45865)</li>
 		<li>[Fix] Move post bump information markup to the template. (Bug #34295 - Patch by bantu)</li>
 		<li>[Change] Change the data format of the default file ACM to be more secure from tampering and have better performance.</li>
+		<li>[Change] Add index on log_time to the log table to prevent slowdown on boards with many log entries. (Bug #44665 - Patch by bantu)</li>
 		<li>[Feature] Backported 3.2 captcha plugins.</li>
 		<li>[Feature] Introduced new ACM plugins:
 			<ul>
diff --git a/phpBB/install/database_update.php b/phpBB/install/database_update.php
index a77896c470..171a8f1fc6 100644
--- a/phpBB/install/database_update.php
+++ b/phpBB/install/database_update.php
@@ -678,8 +678,14 @@ function database_update_info()
 		// No changes from 3.0.5-RC1 to 3.0.5
 		'3.0.5-RC1'		=> array(),
 
-		// No changes from 3.0.5
-		'3.0.5'		=> array(),
+		// Changes from 3.0.5
+		'3.0.5'		=> array(
+			'add_index'		=> array(
+				LOG_TABLE			=> array(
+					'log_time'		=> array('log_time'),
+				),
+			),
+		),
 	);
 }
 
diff --git a/phpBB/install/schemas/firebird_schema.sql b/phpBB/install/schemas/firebird_schema.sql
index fecbc61dc1..e6041e6c32 100644
--- a/phpBB/install/schemas/firebird_schema.sql
+++ b/phpBB/install/schemas/firebird_schema.sql
@@ -526,6 +526,7 @@ CREATE TABLE phpbb_log (
 ALTER TABLE phpbb_log ADD PRIMARY KEY (log_id);;
 
 CREATE INDEX phpbb_log_log_type ON phpbb_log(log_type);;
+CREATE INDEX phpbb_log_log_time ON phpbb_log(log_time);;
 CREATE INDEX phpbb_log_forum_id ON phpbb_log(forum_id);;
 CREATE INDEX phpbb_log_topic_id ON phpbb_log(topic_id);;
 CREATE INDEX phpbb_log_reportee_id ON phpbb_log(reportee_id);;
diff --git a/phpBB/install/schemas/mssql_schema.sql b/phpBB/install/schemas/mssql_schema.sql
index 8600fdb1e0..43c4c06d2d 100644
--- a/phpBB/install/schemas/mssql_schema.sql
+++ b/phpBB/install/schemas/mssql_schema.sql
@@ -636,6 +636,9 @@ GO
 CREATE  INDEX [log_type] ON [phpbb_log]([log_type]) ON [PRIMARY]
 GO
 
+CREATE  INDEX [log_time] ON [phpbb_log]([log_time]) ON [PRIMARY]
+GO
+
 CREATE  INDEX [forum_id] ON [phpbb_log]([forum_id]) ON [PRIMARY]
 GO
 
diff --git a/phpBB/install/schemas/mysql_40_schema.sql b/phpBB/install/schemas/mysql_40_schema.sql
index 146c58904c..5d3e4db7de 100644
--- a/phpBB/install/schemas/mysql_40_schema.sql
+++ b/phpBB/install/schemas/mysql_40_schema.sql
@@ -359,6 +359,7 @@ CREATE TABLE phpbb_log (
 	log_data mediumblob NOT NULL,
 	PRIMARY KEY (log_id),
 	KEY log_type (log_type),
+	KEY log_time (log_time),
 	KEY forum_id (forum_id),
 	KEY topic_id (topic_id),
 	KEY reportee_id (reportee_id),
diff --git a/phpBB/install/schemas/mysql_41_schema.sql b/phpBB/install/schemas/mysql_41_schema.sql
index 81f8266f4d..f4e6fdefdc 100644
--- a/phpBB/install/schemas/mysql_41_schema.sql
+++ b/phpBB/install/schemas/mysql_41_schema.sql
@@ -359,6 +359,7 @@ CREATE TABLE phpbb_log (
 	log_data mediumtext NOT NULL,
 	PRIMARY KEY (log_id),
 	KEY log_type (log_type),
+	KEY log_time (log_time),
 	KEY forum_id (forum_id),
 	KEY topic_id (topic_id),
 	KEY reportee_id (reportee_id),
diff --git a/phpBB/install/schemas/oracle_schema.sql b/phpBB/install/schemas/oracle_schema.sql
index 50f3ee1f80..64e1f8b8c0 100644
--- a/phpBB/install/schemas/oracle_schema.sql
+++ b/phpBB/install/schemas/oracle_schema.sql
@@ -712,6 +712,8 @@ CREATE TABLE phpbb_log (
 
 CREATE INDEX phpbb_log_log_type ON phpbb_log (log_type)
 /
+CREATE INDEX phpbb_log_log_time ON phpbb_log (log_time)
+/
 CREATE INDEX phpbb_log_forum_id ON phpbb_log (forum_id)
 /
 CREATE INDEX phpbb_log_topic_id ON phpbb_log (topic_id)
diff --git a/phpBB/install/schemas/postgres_schema.sql b/phpBB/install/schemas/postgres_schema.sql
index 9736363104..7eccad2585 100644
--- a/phpBB/install/schemas/postgres_schema.sql
+++ b/phpBB/install/schemas/postgres_schema.sql
@@ -516,6 +516,7 @@ CREATE TABLE phpbb_log (
 );
 
 CREATE INDEX phpbb_log_log_type ON phpbb_log (log_type);
+CREATE INDEX phpbb_log_log_time ON phpbb_log (log_time);
 CREATE INDEX phpbb_log_forum_id ON phpbb_log (forum_id);
 CREATE INDEX phpbb_log_topic_id ON phpbb_log (topic_id);
 CREATE INDEX phpbb_log_reportee_id ON phpbb_log (reportee_id);
diff --git a/phpBB/install/schemas/sqlite_schema.sql b/phpBB/install/schemas/sqlite_schema.sql
index 36686955a9..43f83fc989 100644
--- a/phpBB/install/schemas/sqlite_schema.sql
+++ b/phpBB/install/schemas/sqlite_schema.sql
@@ -349,6 +349,7 @@ CREATE TABLE phpbb_log (
 );
 
 CREATE INDEX phpbb_log_log_type ON phpbb_log (log_type);
+CREATE INDEX phpbb_log_log_time ON phpbb_log (log_time);
 CREATE INDEX phpbb_log_forum_id ON phpbb_log (forum_id);
 CREATE INDEX phpbb_log_topic_id ON phpbb_log (topic_id);
 CREATE INDEX phpbb_log_reportee_id ON phpbb_log (reportee_id);