diff --git a/lib/matplotlib/axes.py b/lib/matplotlib/axes.py
index 31ce9e2bf3a4..df99a01d6697 100644
--- a/lib/matplotlib/axes.py
+++ b/lib/matplotlib/axes.py
@@ -16,6 +16,7 @@
 import matplotlib.collections as mcoll
 import matplotlib.colors as mcolors
 import matplotlib.contour as mcontour
+import matplotlib.dates as _ # <-registers a date unit converter 
 from matplotlib import docstring
 import matplotlib.font_manager as font_manager
 import matplotlib.image as mimage