diff --git a/phpBB/includes/acp/acp_users.php b/phpBB/includes/acp/acp_users.php
index 70e08f79f2..61d08a49cf 100644
--- a/phpBB/includes/acp/acp_users.php
+++ b/phpBB/includes/acp/acp_users.php
@@ -172,8 +172,7 @@ class acp_users
 
 				if ($submit)
 				{
-					// You can't delete the founder
-					if ($delete && $user_row['user_type'] != USER_FOUNDER)
+					if ($delete)
 					{
 						if (!$auth->acl_get('a_userdel'))
 						{
@@ -186,6 +185,12 @@ class acp_users
 							trigger_error($user->lang['CANNOT_REMOVE_ANONYMOUS'] . adm_back_link($this->u_action . '&u=' . $user_id), E_USER_WARNING);
 						}
 
+						// Founders can not be deleted.
+						if ($user_row['user_type'] == USER_FOUNDER)
+						{
+							trigger_error($user->lang['CANNOT_REMOVE_FOUNDER'] . adm_back_link($this->u_action . '&u=' . $user_id), E_USER_WARNING);
+						}
+
 						if ($user_id == $user->data['user_id'])
 						{
 							trigger_error($user->lang['CANNOT_REMOVE_YOURSELF'] . adm_back_link($this->u_action . '&u=' . $user_id), E_USER_WARNING);
diff --git a/phpBB/language/en/acp/users.php b/phpBB/language/en/acp/users.php
index 3b82a7022d..25e5ff8269 100644
--- a/phpBB/language/en/acp/users.php
+++ b/phpBB/language/en/acp/users.php
@@ -52,6 +52,7 @@ $lang = array_merge($lang, array(
 	'CANNOT_FORCE_REACT_FOUNDER'	=> 'You are not allowed to force reactivation on founder accounts.',
 	'CANNOT_FORCE_REACT_YOURSELF'	=> 'You are not allowed to force reactivation of your own account.',
 	'CANNOT_REMOVE_ANONYMOUS'		=> 'You are not able to remove the guest user account.',
+	'CANNOT_REMOVE_FOUNDER'			=> 'You are not allowed to remove founder accounts.',
 	'CANNOT_REMOVE_YOURSELF'		=> 'You are not allowed to remove your own user account.',
 	'CANNOT_SET_FOUNDER_IGNORED'	=> 'You are not able to promote ignored users to be founders.',
 	'CANNOT_SET_FOUNDER_INACTIVE'	=> 'You need to activate users before you promote them to founders, only activated users are able to be promoted.',
diff --git a/tests/functional/acp_users_test.php b/tests/functional/acp_users_test.php
new file mode 100644
index 0000000000..50d9a67dc1
--- /dev/null
+++ b/tests/functional/acp_users_test.php
@@ -0,0 +1,45 @@
+<?php
+/**
+*
+* @package testing
+* @copyright (c) 2014 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+/**
+* @group functional
+*/
+class phpbb_functional_acp_users_test extends phpbb_functional_test_case
+{
+	public function setUp()
+	{
+		parent::setUp();
+
+		$this->login();
+		$this->admin_login();
+		$this->add_lang('acp/users');
+	}
+
+	public function test_founder_deletion()
+	{
+		$username = 'founder-account';
+		$user_id = $this->create_user($username);
+		$this->make_founder($user_id);
+
+		$crawler = self::request('GET', "adm/index.php?i=users&mode=overview&u=$user_id&sid={$this->sid}");
+		$form = $crawler->filter('#user_delete')->selectButton($this->lang('SUBMIT'))->form();
+		$crawler = self::submit($form);
+		$this->assertContains($this->lang('CANNOT_REMOVE_FOUNDER'), $this->get_content());
+	}
+
+	protected function make_founder($user_id)
+	{
+		$crawler = self::request('GET', "adm/index.php?i=users&mode=overview&u=$user_id&sid={$this->sid}");
+		$form = $crawler->filter('#user_overview')->selectButton($this->lang('SUBMIT'))->form();
+		$data = array('user_founder' => '1');
+		$form->setValues($data);
+		$crawler = self::submit($form);
+		$this->assertContains($this->lang('USER_OVERVIEW_UPDATED'), $this->get_content());
+	}
+}
diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index 00b31212b2..5dfe07d380 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -423,6 +423,15 @@ class phpbb_functional_test_case extends phpbb_test_case
 			$config = array();
 		}
 
+		/*
+		* Add required config entries to the config array to prevent
+		* set_config() sending an INSERT query for already existing entries,
+		* resulting in a SQL error.
+		* This is because set_config() first sends an UPDATE query, then checks
+		* sql_affectedrows() which can be 0 (e.g. on MySQL) when the new
+		* data is already there.
+		*/
+		$config['newest_user_colour'] = '';
 		$config['rand_seed'] = '';
 		$config['rand_seed_last_update'] = time() + 600;