diff --git a/README.md b/README.md
index 79dd0bd..b436df5 100644
--- a/README.md
+++ b/README.md
@@ -68,6 +68,9 @@ Then, Maxfield can be launched on Windows from any folder via
 	C:\Users\username\Documents\maxfield\env\Scripts\activate
 	python C:\Users\username\Documents\maxfield\bin\maxfield-plan
 
+N.B. There is a bug with the latest version of `ortools`, so we use
+an older version. See: https://github.com/google/or-tools/issues/3202
+
 ### Example
 
 The `example` directory includes the Maxfield output for the portal
diff --git a/setup.py b/setup.py
index 4998eb7..cbf5e2a 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@
     author='Trey V. Wenger',
     author_email='tvwenger@gmail.com',
     packages=['maxfield'],
-    install_requires=['numpy', 'networkx', 'scipy', 'ortools',
+    install_requires=['numpy', 'networkx', 'scipy', 'ortools==8.2.8710',
                       'matplotlib', 'imageio', 'pygifsicle'],
     scripts=['bin/maxfield-plan'],
 )