diff --git a/src/Symfony/Component/Config/Resource/ClassExistenceResource.php b/src/Symfony/Component/Config/Resource/ClassExistenceResource.php
index 1ba8e7624832..340e28f245a8 100644
--- a/src/Symfony/Component/Config/Resource/ClassExistenceResource.php
+++ b/src/Symfony/Component/Config/Resource/ClassExistenceResource.php
@@ -191,15 +191,17 @@ public static function throwOnRequiredClass($class, \Exception $previous = null)
             }
 
             $props = [
-                'file' => $trace[$i]['file'],
-                'line' => $trace[$i]['line'],
+                'file' => isset($trace[$i]['file']) ? $trace[$i]['file'] : null,
+                'line' => isset($trace[$i]['line']) ? $trace[$i]['line'] : null,
                 'trace' => \array_slice($trace, 1 + $i),
             ];
 
             foreach ($props as $p => $v) {
-                $r = new \ReflectionProperty('Exception', $p);
-                $r->setAccessible(true);
-                $r->setValue($e, $v);
+                if (null !== $v) {
+                    $r = new \ReflectionProperty('Exception', $p);
+                    $r->setAccessible(true);
+                    $r->setValue($e, $v);
+                }
             }
         }