diff --git a/scrapy/contrib/throttle.py b/scrapy/contrib/throttle.py
index 3782efc29..1d9d3b355 100644
--- a/scrapy/contrib/throttle.py
+++ b/scrapy/contrib/throttle.py
@@ -66,7 +66,7 @@ class AutoThrottle(object):
     DEBUG = 0
 
     def __init__(self):
-        if not settings.getbool('AUTOTHROTTLE_ENABLED', True):
+        if not settings.getbool('AUTOTHROTTLE_ENABLED'):
             raise NotConfigured
         dispatcher.connect(self.spider_opened, signal=signals.spider_opened)
         dispatcher.connect(self.spider_closed, signal=signals.spider_closed)
diff --git a/scrapy/settings/default_settings.py b/scrapy/settings/default_settings.py
index 9ff886d1d..4bc349683 100644
--- a/scrapy/settings/default_settings.py
+++ b/scrapy/settings/default_settings.py
@@ -126,6 +126,7 @@ EXTENSIONS_BASE = {
     'scrapy.contrib.closespider.CloseSpider': 0,
     'scrapy.contrib.feedexport.FeedExporter': 0,
     'scrapy.contrib.spidercontext.SpiderContext': 0,
+    'scrapy.contrib.throttle.AutoThrottle': 0,
 }
 
 FEED_URI = None