diff --git a/lib/Doctrine/ORM/Mapping/Driver/DoctrineAnnotations.php b/lib/Doctrine/ORM/Mapping/Driver/DoctrineAnnotations.php
index fb7871c74..435676566 100644
--- a/lib/Doctrine/ORM/Mapping/Driver/DoctrineAnnotations.php
+++ b/lib/Doctrine/ORM/Mapping/Driver/DoctrineAnnotations.php
@@ -114,8 +114,8 @@ final class Index extends Annotation {
 final class JoinTable extends Annotation {
     public $name;
     public $schema;
-    public $joinColumns;
-    public $inverseJoinColumns;
+    public $joinColumns = array();
+    public $inverseJoinColumns = array();
 }
 final class SequenceGenerator extends Annotation {
     public $sequenceName;