diff --git a/.circleci/config.yml b/.circleci/config.yml
index 838e11c84b37..e70b1befe053 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -67,8 +67,9 @@ commands:
       - run:
           name: Install Python dependencies
           command: |
-            python -m pip install --user numpy<< parameters.numpy_version >> codecov coverage
-            python -m pip install --user -r requirements/doc/doc-requirements.txt
+            python -m pip install --user \
+                numpy<< parameters.numpy_version >> codecov coverage \
+                -r requirements/doc/doc-requirements.txt
 
   mpl-install:
     steps:
diff --git a/examples/units/basic_units.py b/examples/units/basic_units.py
index 0e62db1233e6..727b538ec183 100644
--- a/examples/units/basic_units.py
+++ b/examples/units/basic_units.py
@@ -5,6 +5,7 @@
 
 """
 
+from distutils.version import LooseVersion
 import math
 
 import numpy as np
@@ -154,8 +155,9 @@ def __str__(self):
     def __len__(self):
         return len(self.value)
 
-    def __getitem__(self, key):
-        return TaggedValue(self.value[key], self.unit)
+    if LooseVersion(np.__version__) >= '1.20':
+        def __getitem__(self, key):
+            return TaggedValue(self.value[key], self.unit)
 
     def __iter__(self):
         # Return a generator expression rather than use `yield`, so that
@@ -218,7 +220,7 @@ def __array_wrap__(self, array, context):
         return TaggedValue(array, self)
 
     def __array__(self, t=None, context=None):
-        ret = np.array([1])
+        ret = np.array(1)
         if t is not None:
             return ret.astype(t)
         else: