diff --git a/doc/environment.yml b/doc/environment.yml
index 2a506d89628..6ae6945ffca 100644
--- a/doc/environment.yml
+++ b/doc/environment.yml
@@ -8,7 +8,7 @@ dependencies:
   - numpydoc
   - seaborn
   - dask
-  - ipython
+  - ipython=4.0.1
   - sphinx
   - netCDF4
   - cartopy
diff --git a/doc/examples/multidimensional-coords.rst b/doc/examples/multidimensional-coords.rst
index be9c3a11855..a54e6058921 100644
--- a/doc/examples/multidimensional-coords.rst
+++ b/doc/examples/multidimensional-coords.rst
@@ -15,6 +15,7 @@ such datasets.
     import numpy as np
     import pandas as pd
     import xarray as xr
+    import netCDF4
     import cartopy.crs as ccrs
     import matplotlib.pyplot as plt
 
diff --git a/readthedocs.yml b/readthedocs.yml
index bed0bd5e332..0129abe15aa 100644
--- a/readthedocs.yml
+++ b/readthedocs.yml
@@ -1,5 +1,5 @@
 conda:
     file: doc/environment.yml
 python:
-   version: 2
+   version: 3
    setup_py_install: true