diff --git a/doc/conf.py b/doc/conf.py
index 0166afa9..3a1350bb 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -116,7 +116,7 @@ class Mock(object):
 
 MOCK_MODULES = ['pylab', 'matplotlib']#'matplotlib', 'matplotlib.color', 'matplotlib.pyplot', 'pylab' ]
 for mod_name in MOCK_MODULES:
-    sys.modules[mod_name] = mock.Mock()
+    sys.modules[mod_name] = Mock()
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the