diff --git a/environment.yml b/environment.yml
index c001a42..a65c2a4 100644
--- a/environment.yml
+++ b/environment.yml
@@ -8,6 +8,7 @@ dependencies:
   - pip
   - pip:
       - otter-grader==4.3.2
+      - numpy==1.22.0
       - datascience==0.17.5
       # Allow users to download their home directories
       - jupyter-tree-download