diff --git a/ci/envs/38-latest-defaults.yaml b/ci/envs/38-latest-defaults.yaml
index a4c4ef7..8dcf6f3 100644
--- a/ci/envs/38-latest-defaults.yaml
+++ b/ci/envs/38-latest-defaults.yaml
@@ -4,6 +4,7 @@ channels:
 dependencies:
   - python=3.8
   # required
+  - numpy=1.21  # pin to < 1.23 for compat with older shapely on defaults channel
   - pandas
   - shapely
   - fiona