diff -r aacf4fcdd4dd -r 7f307b98889b docs/conf.py
--- a/docs/conf.py	Thu Dec 07 17:54:46 2017 +0200
+++ b/docs/conf.py	Thu Dec 07 18:11:26 2017 +0200
@@ -32,7 +32,7 @@
         def __getattr__(cls, name):
                 return MagicMock()
 
-    MOCK_MODULES = ['netCDF4', 'numpy', 'scipy',]
+    MOCK_MODULES = ['netCDF4', 'numpy', 'scipy', 'matplotlib']
     sys.modules.update((mod_name, Mock()) for mod_name in MOCK_MODULES)
 
 # -- General configuration ------------------------------------------------