diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f19d139b1..8a4861851 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -158,7 +158,7 @@ jobs:
       run: |
         conda create --yes --prefix ./coffea-conda-test-env -c conda-forge python=${{ matrix.python-version }} ndcctools uv
         conda activate ./coffea-conda-test-env
-        uv pip install --system .
+        uv pip install --system . 'dask<2024.12.0'
         uv pip install --system pytest
     - name: Test with pytest
       run: |