diff --git a/.github/workflows/ompi_mpi4py.yaml b/.github/workflows/ompi_mpi4py.yaml
index 2510e3d1547..082bd4adaf3 100644
--- a/.github/workflows/ompi_mpi4py.yaml
+++ b/.github/workflows/ompi_mpi4py.yaml
@@ -97,6 +97,10 @@ jobs:
       run:  mpiexec -n 3 python test/main.py -v -f
       if:   ${{ true }}
       timeout-minutes: 10
+    - name: Test mpi4py (np=4)
+      run:  mpiexec -n 4 python test/main.py -v -f
+      if:   ${{ true }}
+      timeout-minutes: 20
     - name: Test mpi4py (np=5)
       run:  mpiexec -n 5 python test/main.py -v -f
       if:   ${{ true }}