diff --git a/phpBB/phpbb/template/twig/twig.php b/phpBB/phpbb/template/twig/twig.php
index aba1d3d099..f9c45a57fe 100644
--- a/phpBB/phpbb/template/twig/twig.php
+++ b/phpBB/phpbb/template/twig/twig.php
@@ -88,7 +88,10 @@ class twig extends \phpbb\template\base
 
 		foreach ($extensions as $extension)
 		{
-			$this->twig->addExtension($extension);
+			if (!$this->twig->hasExtension(get_class($extension)))
+			{
+				$this->twig->addExtension($extension);
+			}
 		}
 
 		// Add admin namespace