diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0f17161362..1a79936f0a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -96,13 +96,15 @@ jobs:
           sudo apt -y install parallel
           . ../firedrake_venv/bin/activate
           python "$(which firedrake-clean)"
-          python -m pip install pytest-timeout ipympl pytest-split
+          python -m pip install pytest-timeout ipympl pytest-split pytest-xdist
           python -m pip list
 
       - name: Run tests (nprocs = 1)
         run: |
+          : # Use pytest-xdist here so we can have a single collated output (not possible
+          : # for parallel tests)
           . ../firedrake_venv/bin/activate
-          firedrake-run-split-tests 1 12 "$EXTRA_PYTEST_ARGS --junit-xml=firedrake1_{#}.xml"
+          firedrake-run-split-tests 1 1 "-n 12 $EXTRA_PYTEST_ARGS --junit-xml=firedrake1_{#}.xml"
 
       - name: Run tests (nprocs = 2)
         # Run even if earlier tests failed