diff --git a/docs/ref/settings.rst b/docs/ref/settings.rst
index 06bc4b649..5c61b3675 100644
--- a/docs/ref/settings.rst
+++ b/docs/ref/settings.rst
@@ -11,17 +11,6 @@ to any particular component. In that case the module of that component will be
 shown, typically an extension, middleware or pipeline. It also means that the
 component must be enabled in order for the setting to have any effect.
 
-.. setting:: ADAPTORS_DEBUG
-
-ADAPTORS_DEBUG
---------------
-
-Default: ``False``
-
-Enable debug mode for adaptors. 
-
-See :ref:`topics-adaptors`.
-
 .. setting:: BOT_NAME
 
 BOT_NAME
diff --git a/scrapy/conf/default_settings.py b/scrapy/conf/default_settings.py
index b901241a1..e895c88bc 100644
--- a/scrapy/conf/default_settings.py
+++ b/scrapy/conf/default_settings.py
@@ -15,8 +15,6 @@ Scrapy developers, if you add a setting here remember to:
 
 from os.path import join, abspath, dirname
 
-ADAPTORS_DEBUG = False
-
 BOT_NAME = 'scrapybot'
 BOT_VERSION = '1.0'