diff --git a/phpBB/includes/functions_compatibility.php b/phpBB/includes/functions_compatibility.php
index d2e3979216..38b9cb40dc 100644
--- a/phpBB/includes/functions_compatibility.php
+++ b/phpBB/includes/functions_compatibility.php
@@ -19,104 +19,6 @@ if (!defined('IN_PHPBB'))
 	exit;
 }
 
-/**
- * Load the autoloaders added by the extensions.
- *
- * @param string $phpbb_root_path Path to the phpbb root directory.
- */
-function phpbb_load_extensions_autoloaders($phpbb_root_path)
-{
-	$iterator = new \phpbb\finder\recursive_path_iterator(
-		$phpbb_root_path . 'ext/',
-		\RecursiveIteratorIterator::SELF_FIRST,
-		\FilesystemIterator::SKIP_DOTS | \FilesystemIterator::FOLLOW_SYMLINKS
-	);
-	$iterator->setMaxDepth(2);
-
-	foreach ($iterator as $file_info)
-	{
-		if ($file_info->getFilename() === 'vendor' && $iterator->getDepth() === 2)
-		{
-			$filename = $file_info->getRealPath() . '/autoload.php';
-			if (file_exists($filename))
-			{
-				require $filename;
-			}
-		}
-	}
-}
-
-/**
-* Converts query string (GET) parameters in request into hidden fields.
-*
-* Useful for forwarding GET parameters when submitting forms with GET method.
-*
-* It is possible to omit some of the GET parameters, which is useful if
-* they are specified in the form being submitted.
-*
-* sid is always omitted.
-*
-* @param \phpbb\request\request $request Request object
-* @param array $exclude A list of variable names that should not be forwarded
-* @return string HTML with hidden fields
-*
-* @deprecated 3.2.10 (To be removed 4.0.0)
-*/
-function phpbb_build_hidden_fields_for_query_params($request, $exclude = null)
-{
-	$names = $request->variable_names(\phpbb\request\request_interface::GET);
-	$hidden = '';
-	foreach ($names as $name)
-	{
-		// Sessions are dealt with elsewhere, omit sid always
-		if ($name == 'sid')
-		{
-			continue;
-		}
-
-		// Omit any additional parameters requested
-		if (!empty($exclude) && in_array($name, $exclude))
-		{
-			continue;
-		}
-
-		$escaped_name = phpbb_quoteattr($name);
-
-		// Note: we might retrieve the variable from POST or cookies
-		// here. To avoid exposing cookies, skip variables that are
-		// overwritten somewhere other than GET entirely.
-		$value = $request->variable($name, '', true);
-		$get_value = $request->variable($name, '', true, \phpbb\request\request_interface::GET);
-		if ($value === $get_value)
-		{
-			$escaped_value = phpbb_quoteattr($value);
-			$hidden .= "<input type='hidden' name=$escaped_name value=$escaped_value />";
-		}
-	}
-	return $hidden;
-}
-
-/**
-* Delete all PM(s) for a given user and delete the ones without references
-*
-* @param	int		$user_id	ID of the user whose private messages we want to delete
-*
-* @return	boolean		False if there were no pms found, true otherwise.
-*
-* @deprecated 3.2.10 (To be removed 4.0.0)
-*/
-function phpbb_delete_user_pms($user_id)
-{
-	$user_id = (int) $user_id;
-
-	if (!$user_id)
-	{
-		return false;
-	}
-
-	return phpbb_delete_users_pms(array($user_id));
-}
-
 /**
 * Casts a numeric string $input to an appropriate numeric type (i.e. integer or float)
 *
diff --git a/tests/functions/build_hidden_fields_for_query_params_test.php b/tests/functions/build_hidden_fields_for_query_params_test.php
deleted file mode 100644
index aee7a569d4..0000000000
--- a/tests/functions/build_hidden_fields_for_query_params_test.php
+++ /dev/null
@@ -1,73 +0,0 @@
-<?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.
-*
-*/
-
-class phpbb_build_hidden_fields_for_query_params_test extends phpbb_test_case
-{
-	public function build_hidden_fields_for_query_params_test_data()
-	{
-		return array(
-			// get
-			// post
-			// exclude
-			// expected
-			array(
-				array('foo' => 'bar'),
-				array(),
-				array(),
-				"<input type='hidden' name=\"foo\" value=\"bar\" />",
-			),
-			array(
-				array('foo' => 'bar', 'a' => 'b'),
-				array(),
-				array(),
-				"<input type='hidden' name=\"foo\" value=\"bar\" /><input type='hidden' name=\"a\" value=\"b\" />",
-			),
-			array(
-				array('a' => 'quote"', 'b' => '<less>'),
-				array(),
-				array(),
-				"<input type='hidden' name=\"a\" value='quote\"' /><input type='hidden' name=\"b\" value=\"&lt;less&gt;\" />",
-			),
-			array(
-				array('a' => "quotes'\""),
-				array(),
-				array(),
-				"<input type='hidden' name=\"a\" value=\"quotes'&quot;\" />",
-			),
-			array(
-				array('foo' => 'bar', 'a' => 'b'),
-				array('a' => 'c'),
-				array(),
-				"<input type='hidden' name=\"foo\" value=\"bar\" />",
-			),
-			// strict equality check
-			array(
-				array('foo' => 'bar', 'a' => '0'),
-				array('a' => ''),
-				array(),
-				"<input type='hidden' name=\"foo\" value=\"bar\" />",
-			),
-		);
-	}
-
-	/**
-	* @dataProvider build_hidden_fields_for_query_params_test_data
-	*/
-	public function test_build_hidden_fields_for_query_params($get, $post, $exclude, $expected)
-	{
-		$request = new phpbb_mock_request($get, $post);
-		$result = phpbb_build_hidden_fields_for_query_params($request, $exclude);
-
-		$this->assertEquals($expected, $result);
-	}
-}
diff --git a/tests/privmsgs/delete_user_pms_test.php b/tests/privmsgs/delete_user_pms_test.php
index a50240aae3..e618d7c2e6 100644
--- a/tests/privmsgs/delete_user_pms_test.php
+++ b/tests/privmsgs/delete_user_pms_test.php
@@ -97,7 +97,7 @@ class phpbb_privmsgs_delete_user_pms_test extends phpbb_database_test_case
 		// Works as a workaround for tests
 		$phpbb_container->set('attachment.manager', new \phpbb\attachment\delete(new \phpbb\config\config(array()), $db, new \phpbb_mock_event_dispatcher(), new \phpbb\attachment\resync($db), $storage));
 
-		phpbb_delete_user_pms($delete_user);
+		phpbb_delete_users_pms([$delete_user]);
 
 		$sql = 'SELECT msg_id
 			FROM ' . PRIVMSGS_TABLE;