diff --git a/.github/workflows/ci-additional.yaml b/.github/workflows/ci-additional.yaml
index 0b59e199b39..6e75587a14b 100644
--- a/.github/workflows/ci-additional.yaml
+++ b/.github/workflows/ci-additional.yaml
@@ -96,7 +96,7 @@ jobs:
           python -c "import xarray"
       - name: Run tests
         run: |
-          python -m pytest -n 4 \
+          python -m pytest \
              --cov=xarray \
              --cov-report=xml \
              $PYTEST_EXTRA_FLAGS
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 82e21a4f46c..6ac9d30ab3b 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -87,7 +87,7 @@ jobs:
         run: |
           python -c "import xarray"
       - name: Run tests
-        run: python -m pytest -n 4
+        run: python -m pytest
           --cov=xarray
           --cov-report=xml
           --junitxml=pytest.xml