diff --git a/.github/workflows/ci-additional.yaml b/.github/workflows/ci-additional.yaml
index 935729c055f..dd18aa365d5 100644
--- a/.github/workflows/ci-additional.yaml
+++ b/.github/workflows/ci-additional.yaml
@@ -119,7 +119,7 @@ jobs:
           python xarray/util/print_versions.py
       - name: Install mypy
         run: |
-          python -m pip install mypy
+          python -m pip install 'mypy<0.990'
 
       - name: Run mypy
         run: |