diff --git a/lib/matplotlib/sphinxext/plot_directive.py b/lib/matplotlib/sphinxext/plot_directive.py
index e36ca70361a0..8451d4ef3308 100644
--- a/lib/matplotlib/sphinxext/plot_directive.py
+++ b/lib/matplotlib/sphinxext/plot_directive.py
@@ -164,7 +164,7 @@
     plt.switch_backend("Agg")
 else:
     import matplotlib.pyplot as plt
-from matplotlib import _pylab_helpers
+from matplotlib import _pylab_helpers, cbook
 
 __version__ = 2