diff --git a/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php b/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php
index 73ee17b..a3b0b2a 100644
--- a/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php
+++ b/core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php
@@ -24,7 +24,7 @@ public function process(ContainerBuilder $container) {
       $reflection = new \ReflectionClass($class_name);
       // We use the class names as hash in order to invalidate on new extensions
       // and mtime for every time we change an existing file.
-      $twig_extension_hash .= $class_name . filemtime($reflection->getFileName());
+      $twig_extension_hash .= $class_name;
     }
 
     $container->setParameter('twig_extension_hash', Crypt::hashBase64($twig_extension_hash));