diff --git a/src/Symfony/Component/Config/ResourceCheckerConfigCache.php b/src/Symfony/Component/Config/ResourceCheckerConfigCache.php
index 933cf0f9c7b84..53fc245d35a4c 100644
--- a/src/Symfony/Component/Config/ResourceCheckerConfigCache.php
+++ b/src/Symfony/Component/Config/ResourceCheckerConfigCache.php
@@ -159,7 +159,7 @@ private function safelyUnserialize($file)
         $signalingException = new \UnexpectedValueException();
         $prevUnserializeHandler = ini_set('unserialize_callback_func', '');
         $prevErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context = []) use (&$prevErrorHandler, $signalingException) {
-            if (E_WARNING === $type && 'Class __PHP_Incomplete_Class has no unserializer' === $msg) {
+            if (__FILE__ === $file && preg_match('/^Class .* has no unserializer$/', $msg)) {
                 throw $signalingException;
             }