diff --git a/doc/conf.py b/doc/conf.py
index e178e42d8257f0855ce2e0e0303c9adcff2905cf..86156f016fcd07ddee2ddb23ba82842ea44f975d 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -31,7 +31,6 @@ extensions = [
   'sphinx.ext.autosummary',
   'sphinx.ext.doctest',
   'sphinx.ext.intersphinx',
-  'matplotlib.sphinxext.plot_directive',
   ]
 
 # The viewcode extension appeared only on Sphinx >= 1.0.0