diff --git a/scrapy/spider.py b/scrapy/spider.py
index 530dc916a..b2d2f0e46 100644
--- a/scrapy/spider.py
+++ b/scrapy/spider.py
@@ -26,8 +26,6 @@ class BaseSpider(object_ref):
         self.__dict__.update(kwargs)
         if not hasattr(self, 'start_urls'):
             self.start_urls = []
-        if not hasattr(self, 'allowed_domains'):
-            self.allowed_domains = []
 
     def log(self, message, level=log.DEBUG):
         """Log the given messages at the given log level. Always use this
diff --git a/scrapy/tests/test_spider.py b/scrapy/tests/test_spider.py
index 4dcb7d47a..c1401fa83 100644
--- a/scrapy/tests/test_spider.py
+++ b/scrapy/tests/test_spider.py
@@ -24,7 +24,6 @@ class BaseSpiderTest(unittest.TestCase):
         spider = self.spider_class("example.com")
         self.assertEqual(spider.name, 'example.com')
         self.assertEqual(spider.start_urls, [])
-        self.assertEqual(spider.allowed_domains, [])
 
     def test_spider_args(self):
         """Constructor arguments are assigned to spider attributes"""