diff --git a/.github/workflows/pytest.yaml b/.github/workflows/pytest.yaml
index ec09e55352..3105492984 100644
--- a/.github/workflows/pytest.yaml
+++ b/.github/workflows/pytest.yaml
@@ -109,6 +109,10 @@ jobs:
 
         pip install .[docs,tests] ${{ matrix.upstream.extra-deps }}
 
+        # TEMPORARY Work around unionai-oss/pandera#1685;
+        # see https://github.com/khaeru/genno/issues/140
+        pip install "numpy < 2"
+
     - name: Configure local data path
       run: |
         mkdir -p message-local-data/cache