diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 75345e9e..f7166f15 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -53,4 +53,4 @@ jobs:
         run: python -m pip install -e .
 
       - name: Run pytest
-        run: pytest -n 4 -v -k "not long and not ffi" --ignore=tests/lib --halmos-options="--debug -st ${{ matrix.parallel }} --storage-layout ${{ matrix.storage-layout }} --solver-timeout-assertion 0 ${{ inputs.halmos-options }}" ${{ inputs.pytest-options }}
+        run: pytest -n 1 -v -k "not long and not ffi" --ignore=tests/lib --halmos-options="--debug -st ${{ matrix.parallel }} --storage-layout ${{ matrix.storage-layout }} --solver-timeout-assertion 0 ${{ inputs.halmos-options }}" ${{ inputs.pytest-options }}