diff --git a/docs/conf.py b/docs/conf.py
index edd6b298..c841a3bc 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -21,16 +21,25 @@
 sys.path.insert(0, os.path.abspath('../'))
 
 # mock
-from unittest.mock import MagicMock
+import mock
+
+MOCK_MODULES = ['numpy', 'scipy', 'matplotlib', 'matplotlib.pyplot',
+                'scipy.interpolate']
+for mod_name in MOCK_MODULES:
+    sys.modules[mod_name] = mock.Mock()
+
+# from unittest.mock import MagicMock
+#
+# class Mock(MagicMock):
+#     @classmethod
+#     def __getattr__(cls, name):
+#             return Mock()
+#
+# MOCK_MODULES = ['pygtk', 'gtk', 'gobject', 'argparse', 'numpy', 'pandas',
+#                 'scipy']
+# sys.modules.update((mod_name, Mock()) for mod_name in MOCK_MODULES)
 
-class Mock(MagicMock):
-    @classmethod
-    def __getattr__(cls, name):
-            return Mock()
 
-MOCK_MODULES = ['pygtk', 'gtk', 'gobject', 'argparse', 'numpy', 'pandas',
-                'scipy']
-sys.modules.update((mod_name, Mock()) for mod_name in MOCK_MODULES)
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.