diff --git a/phpBB/includes/template/twig/extension.php b/phpBB/includes/template/twig/extension.php
index fb9daab500..d7400fde4b 100644
--- a/phpBB/includes/template/twig/extension.php
+++ b/phpBB/includes/template/twig/extension.php
@@ -45,9 +45,14 @@ class phpbb_template_twig_extension extends Twig_Extension
 	public function getOperators()
 	{
 		return array(
-			array(),
 			array(
-				// @todo check if all these are needed (or others) and set precedence correctly
+                '!' => array('precedence' => 50, 'class' => 'Twig_Node_Expression_Unary_Not'),
+			),
+			array(
+				// precedence settings are copied from similar operators in Twig core extension
+				'||' => array('precedence' => 10, 'class' => 'Twig_Node_Expression_Binary_Or', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+				'&&' => array('precedence' => 15, 'class' => 'Twig_Node_Expression_Binary_And', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
+
 				'eq' => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_Equal', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
 
 				'ne' => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_NotEqual', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
@@ -64,9 +69,6 @@ class phpbb_template_twig_extension extends Twig_Extension
 				'lte' => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_LessEqual', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
 				'le' => array('precedence' => 20, 'class' => 'Twig_Node_Expression_Binary_LessEqual', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
 
-				'||' => array('precedence' => 10, 'class' => 'Twig_Node_Expression_Binary_Or', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
-				'&&' => array('precedence' => 15, 'class' => 'Twig_Node_Expression_Binary_And', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
-
                 'mod' => array('precedence' => 60, 'class' => 'Twig_Node_Expression_Binary_Mod', 'associativity' => Twig_ExpressionParser::OPERATOR_LEFT),
             ),
         );