diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 418e8dc51d..8e8bd56af6 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -48,11 +48,16 @@ function set_var(&$result, $var, $type, $multibyte = false)
 *										Default is false, causing all bytes outside the ASCII range (0-127) to be replaced with question marks
 * @param	bool			$cookie		This param is mapped to phpbb_request_interface::COOKIE as the last param for
 * 										phpbb_request_interface::variable for backwards compatability reasons.
+* @param	phpbb_request_interface|null|false	If an instance of phpbb_request_interface is given the instance is stored in
+*										a static variable and used for all further calls where this parameters is null. Until
+*										the function is called with an instance it automatically creates a new phpbb_request
+*										instance on every call. By passing false this per-call instantiation can be restored
+*										after having passed in a phpbb_request_interface instance.
 *
 * @return	mixed	The value of $_REQUEST[$var_name] run through {@link set_var set_var} to ensure that the type is the
 * 					the same as that of $default. If the variable is not set $default is returned.
 */
-function request_var($var_name, $default, $multibyte = false, $cookie = false, phpbb_request_interface $request = null)
+function request_var($var_name, $default, $multibyte = false, $cookie = false, $request = null)
 {
 	// This is all just an ugly hack to add "Dependency Injection" to a function
 	// the only real code is the function call which maps this function to a method.
@@ -67,6 +72,15 @@ function request_var($var_name, $default, $multibyte = false, $cookie = false, p
 			return;
 		}
 	}
+	else if ($request === false)
+	{
+		$static_request = null;
+
+		if (empty($var_name))
+		{
+			return;
+		}
+	}
 
 	$tmp_request = $static_request;
 
@@ -3253,7 +3267,7 @@ function get_preg_expression($mode)
 * Depends on whether installed PHP version supports unicode properties
 *
 * @param string	$word			word template to be replaced
-* @param bool	$use_unicode	whether or not to take advantage of PCRE supporting unicode 
+* @param bool	$use_unicode	whether or not to take advantage of PCRE supporting unicode
 *
 * @return string $preg_expr		regex to use with word censor
 */
diff --git a/tests/request/request_var_test.php b/tests/request/request_var_test.php
index 6a0ede0106..7a45ef2fee 100644
--- a/tests/request/request_var_test.php
+++ b/tests/request/request_var_test.php
@@ -12,6 +12,15 @@ require_once dirname(__FILE__) . '/../../phpBB/includes/utf/utf_tools.php';
 
 class phpbb_request_var_test extends phpbb_test_case
 {
+	/**
+	* Makes sure request_var has its standard behaviour.
+	*/
+	protected function setUp()
+	{
+		parent::setUp();
+		request_var(false, false, false, false, false);
+	}
+
 	/**
 	* @dataProvider request_variables
 	*/