diff --git a/.github/workflows/unittest-flux-mpich.yml b/.github/workflows/unittest-flux-mpich.yml
new file mode 100644
index 00000000..88611b79
--- /dev/null
+++ b/.github/workflows/unittest-flux-mpich.yml
@@ -0,0 +1,40 @@
+name: Unittests-flux-mpich
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Extend environment
+      shell: bash -l {0}
+      timeout-minutes: 5
+      run: |
+        echo -e '- coverage\n- flux-core =0.59.0\n- versioneer =0.28'>> .ci_support/environment-mpich.yml
+        cat .ci_support/environment-mpich.yml
+    - uses: conda-incubator/setup-miniconda@v2.2.0
+      with:
+        python-version: '3.12'
+        mamba-version: "*"
+        channels: conda-forge
+        miniforge-variant: Mambaforge
+        channel-priority: strict
+        auto-update-conda: true
+        environment-file: .ci_support/environment-mpich.yml
+    - name: Test
+      shell: bash -l {0}
+      timeout-minutes: 5
+      run: |
+        pip install . --no-deps --no-build-isolation
+        python -m unittest discover tests
+    - name: Test Flux
+      shell: bash -l {0}
+      timeout-minutes: 5
+      run: >
+        flux start
+        python -m unittest tests/test_flux_executor.py tests/test_executor_backend_flux.py;
\ No newline at end of file
diff --git a/.github/workflows/unittest-flux-openmpi.yml b/.github/workflows/unittest-flux-openmpi.yml
new file mode 100644
index 00000000..80a70328
--- /dev/null
+++ b/.github/workflows/unittest-flux-openmpi.yml
@@ -0,0 +1,45 @@
+name: Unittests-flux-openmpi
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Extend environment
+      shell: bash -l {0}
+      timeout-minutes: 5
+      run: |
+        echo -e '- coverage\n- flux-core =0.59.0\n- flux-pmix=0.5.0\n- versioneer =0.28' >> .ci_support/environment-openmpi.yml
+        cat .ci_support/environment-openmpi.yml
+    - uses: conda-incubator/setup-miniconda@v2.2.0
+      with:
+        python-version: '3.12'
+        mamba-version: "*"
+        channels: conda-forge
+        miniforge-variant: Mambaforge
+        channel-priority: strict
+        auto-update-conda: true
+        environment-file: .ci_support/environment-openmpi.yml
+    - name: Test
+      shell: bash -l {0}
+      timeout-minutes: 5
+      run: |
+        pip install . --no-deps --no-build-isolation
+        coverage run -a --omit="pympipool/_version.py,tests/*" -m unittest discover tests
+    - name: Test Flux with OpenMPI
+      shell: bash -l {0}
+      timeout-minutes: 5
+      run: >
+        flux start
+        coverage run -a --omit="pympipool/_version.py,tests/*" -m unittest tests/test_flux_executor.py tests/test_executor_backend_flux.py;
+        coverage xml
+      env:
+        PYMPIPOOL_PMIX: "pmix"
+    - name: Coveralls
+      uses: coverallsapp/github-action@v2
diff --git a/.github/workflows/unittest-flux.yml b/.github/workflows/unittest-flux.yml
deleted file mode 100644
index d4f048cf..00000000
--- a/.github/workflows/unittest-flux.yml
+++ /dev/null
@@ -1,71 +0,0 @@
-# This workflow is used to run the unittest of pyiron
-
-name: Unittests-flux
-
-on:
-  push:
-    branches: [ main ]
-  pull_request:
-    branches: [ main ]
-
-jobs:
-  build:
-
-    runs-on: ${{ matrix.operating-system }}
-    strategy:
-      matrix:
-        include:
-        - operating-system: ubuntu-latest
-          python-version: '3.12'
-          label: linux-64-py-3-12-openmpi
-          prefix: /Users/runner/miniconda3/envs/my-env
-          environment-file: .ci_support/environment-openmpi.yml
-
-        - operating-system: ubuntu-latest
-          python-version: '3.12'
-          label: linux-64-py-3-12-mpich
-          prefix: /usr/share/miniconda3/envs/my-env
-          environment-file: .ci_support/environment-mpich.yml
-
-    steps:
-    - uses: actions/checkout@v2
-    - name: Extend environment openmpi
-      shell: bash -l {0}
-      timeout-minutes: 5
-      if:  matrix.label == 'linux-64-py-3-12-openmpi'
-      run: |
-        echo -e '- coverage\n- flux-core =0.59.0\n- flux-pmix=0.5.0' >> ${{ matrix.environment-file }}
-        cat ${{ matrix.environment-file }}
-    - name: Extend environment mpich
-      shell: bash -l {0}
-      timeout-minutes: 5
-      if:  matrix.label == 'linux-64-py-3-12-mpich'
-      run: |
-        echo -e '- coverage\n- flux-core =0.59.0' >> ${{ matrix.environment-file }}
-        cat ${{ matrix.environment-file }}
-    - uses: conda-incubator/setup-miniconda@v2.2.0
-      with:
-        python-version: ${{ matrix.python-version }}
-        mamba-version: "*"
-        channels: conda-forge
-        miniforge-variant: Mambaforge
-        channel-priority: strict
-        auto-update-conda: true
-        environment-file: ${{ matrix.environment-file }}
-    - name: Test
-      shell: bash -l {0}
-      timeout-minutes: 5
-      run: |
-        pip install versioneer[toml]==0.29
-        pip install . --no-deps --no-build-isolation
-        coverage run -a --omit="pympipool/_version.py,tests/*" -m unittest discover tests
-    - name: Test Flux
-      shell: bash -l {0}
-      timeout-minutes: 5
-      run: >
-        flux start
-        coverage run -a --omit="pympipool/_version.py,tests/*" -m unittest tests/test_flux_executor.py tests/test_executor_backend_flux.py;
-        coverage xml
-    - name: Coveralls
-      if:  matrix.label == 'linux-64-py-3-12-openmpi'
-      uses: coverallsapp/github-action@v2
diff --git a/tests/test_executor_backend_flux.py b/tests/test_executor_backend_flux.py
index e07064cc..1eb599ee 100644
--- a/tests/test_executor_backend_flux.py
+++ b/tests/test_executor_backend_flux.py
@@ -14,6 +14,7 @@
     )
 
     skip_flux_test = "FLUX_URI" not in os.environ
+    pmi = os.environ.get("PYMPIPOOL_PMIX", None)
 except ImportError:
     skip_flux_test = True
 
@@ -81,6 +82,7 @@ def test_flux_executor_parallel(self):
             executor=self.executor,
             backend="flux",
             block_allocation=True,
+            pmi=pmi,
         ) as exe:
             fs_1 = exe.submit(mpi_funct, 1)
             self.assertEqual(fs_1.result(), [(1, 2, 0), (1, 2, 1)])
@@ -93,6 +95,7 @@ def test_single_task(self):
             executor=self.executor,
             backend="flux",
             block_allocation=True,
+            pmi=pmi,
         ) as p:
             output = p.map(mpi_funct, [1, 2, 3])
         self.assertEqual(
diff --git a/tests/test_flux_executor.py b/tests/test_flux_executor.py
index 2861ebdc..14f6413d 100644
--- a/tests/test_flux_executor.py
+++ b/tests/test_flux_executor.py
@@ -16,6 +16,7 @@
     )
 
     skip_flux_test = "FLUX_URI" not in os.environ
+    pmi = os.environ.get("PYMPIPOOL_PMIX", None)
 except ImportError:
     skip_flux_test = True
 
@@ -69,7 +70,7 @@ def test_flux_executor_threads(self):
 
     def test_flux_executor_parallel(self):
         with PyFluxExecutor(
-            max_workers=1, cores_per_worker=2, executor=self.executor
+            max_workers=1, cores_per_worker=2, executor=self.executor, pmi=pmi
         ) as exe:
             fs_1 = exe.submit(mpi_funct, 1)
             self.assertEqual(fs_1.result(), [(1, 2, 0), (1, 2, 1)])
@@ -77,7 +78,7 @@ def test_flux_executor_parallel(self):
 
     def test_single_task(self):
         with PyFluxExecutor(
-            max_workers=1, cores_per_worker=2, executor=self.executor
+            max_workers=1, cores_per_worker=2, executor=self.executor, pmi=pmi
         ) as p:
             output = p.map(mpi_funct, [1, 2, 3])
         self.assertEqual(