diff --git a/phpBB/includes/acp/acp_board.php b/phpBB/includes/acp/acp_board.php
index 8061265e11..d41a1c010a 100644
--- a/phpBB/includes/acp/acp_board.php
+++ b/phpBB/includes/acp/acp_board.php
@@ -215,8 +215,6 @@ class acp_board
 						'max_post_urls'			=> array('lang' => 'MAX_POST_URLS',			'validate' => 'int:0:9999',		'type' => 'number:0:9999', 'explain' => true),
 						'max_post_font_size'	=> array('lang' => 'MAX_POST_FONT_SIZE',	'validate' => 'int:0:9999',		'type' => 'number:0:9999', 'explain' => true, 'append' => ' %'),
 						'max_quote_depth'		=> array('lang' => 'QUOTE_DEPTH_LIMIT',		'validate' => 'int:0:9999',		'type' => 'number:0:9999', 'explain' => true),
-						'max_post_img_width'	=> array('lang' => 'MAX_POST_IMG_WIDTH',	'validate' => 'int:0:9999',		'type' => 'number:0:9999', 'explain' => true, 'append' => ' ' . $user->lang['PIXEL']),
-						'max_post_img_height'	=> array('lang' => 'MAX_POST_IMG_HEIGHT',	'validate' => 'int:0:9999',		'type' => 'number:0:9999', 'explain' => true, 'append' => ' ' . $user->lang['PIXEL']),
 
 						'legend3'				=> 'MENTIONS',
 						'allow_mentions'		=> array('lang' => 'ALLOW_MENTIONS',	'validate' => 'bool',	'type' => 'radio:yes_no', 'explain' => false),
diff --git a/phpBB/includes/questionnaire/questionnaire.php b/phpBB/includes/questionnaire/questionnaire.php
index cdb70ef2f1..d5eb1daf7c 100644
--- a/phpBB/includes/questionnaire/questionnaire.php
+++ b/phpBB/includes/questionnaire/questionnaire.php
@@ -400,8 +400,6 @@ class phpbb_questionnaire_phpbb_data_provider
 			'max_poll_options' => true,
 			'max_post_chars' => true,
 			'max_post_font_size' => true,
-			'max_post_img_height' => true,
-			'max_post_img_width' => true,
 			'max_post_smilies' => true,
 			'max_post_urls' => true,
 			'max_quote_depth' => true,
diff --git a/phpBB/install/schemas/schema_data.sql b/phpBB/install/schemas/schema_data.sql
index a429d720aa..c3a3ff9876 100644
--- a/phpBB/install/schemas/schema_data.sql
+++ b/phpBB/install/schemas/schema_data.sql
@@ -220,8 +220,6 @@ INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_num_search_key
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_poll_options', '10');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_post_chars', '60000');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_post_font_size', '200');
-INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_post_img_height', '0');
-INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_post_img_width', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_post_smilies', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_post_urls', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('max_quote_depth', '3');
diff --git a/phpBB/phpbb/db/migration/data/v400/remove_flash_v2.php b/phpBB/phpbb/db/migration/data/v400/remove_flash_v2.php
new file mode 100644
index 0000000000..5312cc7c83
--- /dev/null
+++ b/phpBB/phpbb/db/migration/data/v400/remove_flash_v2.php
@@ -0,0 +1,39 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\db\migration\data\v400;
+
+use phpbb\db\migration\migration;
+
+class remove_flash_v2 extends migration
+{
+	public function effectively_installed()
+	{
+		return !$this->config->offsetExists('max_post_img_width');
+	}
+
+	public static function depends_on()
+	{
+		return [
+			'\phpbb\db\migration\data\v400\remove_flash',
+		];
+	}
+
+	public function update_data()
+	{
+		return [
+			['config.remove', ['max_post_img_width']],
+			['config.remove', ['max_post_img_height']],
+		];
+	}
+}
diff --git a/tests/text_processing/message_parser_test.php b/tests/text_processing/message_parser_test.php
index 22496a8505..0f74eacbe6 100644
--- a/tests/text_processing/message_parser_test.php
+++ b/tests/text_processing/message_parser_test.php
@@ -315,26 +315,6 @@ class phpbb_text_processing_message_parser_test extends phpbb_test_case
 				},
 				array('You may only use fonts up to size 120.')
 			),
-			array(
-				'[img]http://example.org/100x100.png[/img]',
-				'<r><IMG src="http://example.org/100x100.png"><s>[img]</s><URL url="http://example.org/100x100.png">http://example.org/100x100.png</URL><e>[/img]</e></IMG></r>',
-				array(true, true, true, true, true, true),
-				function ($phpbb_container)
-				{
-					$phpbb_container->get('config')->set('max_post_img_height', 0);
-					$phpbb_container->get('config')->set('max_post_img_width', 0);
-				}
-			),
-			array(
-				'[img]http://example.org/100x100.png[/img]',
-				'<r><IMG src="http://example.org/100x100.png"><s>[img]</s><URL url="http://example.org/100x100.png">http://example.org/100x100.png</URL><e>[/img]</e></IMG></r>',
-				array(true, true, true, true, true, true),
-				function ($phpbb_container)
-				{
-					$phpbb_container->get('config')->set('max_post_img_height', 100);
-					$phpbb_container->get('config')->set('max_post_img_width', 100);
-				}
-			),
 			array(
 				'[img]http://example.org/100x100.png[/img]',
 				'<r><IMG src="http://example.org/100x100.png"><s>[img]</s><URL url="http://example.org/100x100.png">http://example.org/100x100.png</URL><e>[/img]</e></IMG></r>',