diff --git a/.github/workflows/release-test.yml b/.github/workflows/release-test.yml
index 368ecb1482..e45d0dd311 100644
--- a/.github/workflows/release-test.yml
+++ b/.github/workflows/release-test.yml
@@ -38,16 +38,38 @@ on:
 env:
   DOCKER_MAKE_ARGS: -j
 # split up native and IoT-LAB tasks to parallelize somewhat and prevent
-# to hit Github Limit of 6h per job, can't use matrix because there seems to be
-# some sync happening and the longer running job is killed.
+# to hit Github Limit of 6h per job.
 jobs:
-  native-tasks:
+  tasks:
     runs-on: ubuntu-latest
     timeout-minutes: 360
+    strategy:
+      fail-fast: false
+      matrix:
+        pytest_mark:
+          - "iotlab_creds"
+        include:
+          - pytest_mark: "not iotlab_creds"
+            sudo: "sudo"
     steps:
     - name: Generate .riotgithubtoken
       run: |
         echo '${{ secrets.RIOT_CI_ACCESS_TOKEN }}' > ~/.riotgithubtoken
+    - name: Setup IoT-LAB credentials
+      if: ${{ matrix.pytest_mark == 'iotlab_creds' }}
+      run: |
+        echo '${{ secrets.IOTLABRC }}' > ~/.iotlabrc
+    - name: Setup SSH agent
+      if: ${{ matrix.pytest_mark == 'iotlab_creds' }}
+      uses: webfactory/ssh-agent@v0.4.1
+      with:
+        ssh-private-key: ${{ secrets.IOTLAB_PRIVATE_KEY }}
+    - name: Fetch host key from IoT-LAB saclay site
+      if: ${{ matrix.pytest_mark == 'iotlab_creds' }}
+      run: |
+        IOTLAB_USER=$(cat ~/.iotlabrc | cut -f1 -d:)
+        ssh -oStrictHostKeyChecking=accept-new \
+          ${IOTLAB_USER}@saclay.iot-lab.info exit
     - name: Checkout Release-Specs
       uses: actions/checkout@v2
       with:
@@ -93,7 +115,7 @@ jobs:
         cd Release-Specs
         # definition in env does not work since $GITHUB_WORKSPACE seems not to
         # be accessible
-        sudo \
+        ${{ matrix.sudo }} \
           BUILD_IN_DOCKER=1 \
           DOCKER_MAKE_ARGS=${DOCKER_MAKE_ARGS} \
           DOCKER_ENV_VARS=USEMODULE \
@@ -101,7 +123,7 @@ jobs:
           GITHUB_RUN_ID=${GITHUB_RUN_ID} \
           GITHUB_SERVER_URL=${GITHUB_SERVER_URL} \
           RIOTBASE=${RIOTBASE} \
-          $(which tox) -- ${TOX_ARGS} -m "not iotlab_creds"
+          $(which tox) -- ${TOX_ARGS} -m "${{ matrix.pytest_mark }}"
     - name: junit2html and XML deploy
       if: always()
       run: |
@@ -122,87 +144,3 @@ jobs:
       with:
         name: Test Reports
         path: test-reports/*
-  iotlab-tasks:
-    runs-on: ubuntu-latest
-    timeout-minutes: 360
-    steps:
-    - name: Generate .riotgithubtoken
-      run: |
-        echo '${{ secrets.RIOT_CI_ACCESS_TOKEN }}' > ~/.riotgithubtoken
-    - name: Checkout Release-Specs
-      uses: actions/checkout@v2
-      with:
-        repository: RIOT-OS/Release-Specs
-        path: Release-Specs
-        fetch-depth: 1
-        ref: ${{ github.event.inputs.release_specs_version }}
-    - name: Checkout RIOT
-      uses: actions/checkout@v2
-      with:
-        repository: RIOT-OS/RIOT
-        path: RIOT
-        fetch-depth: 1
-        ref: ${{ github.event.inputs.riot_version }}
-    - name: Set up Python
-      uses: actions/setup-python@v2
-      with:
-        python-version: 3.x
-    - name: Install Python dependencies
-      run: |
-        python -m pip install --upgrade pip
-        python -m pip install tox junit2html
-    - name: Pull riotbuild docker image
-      run: |
-        DOCKER_VERSION="${{ github.event.inputs.docker_version }}"
-        if [ -z "$DOCKER_VERSION" ]; then
-          DOCKER_VERSION="latest"
-        fi
-        docker pull riot/riotbuild:$DOCKER_VERSION
-    - name: Setup IoT-LAB credentials
-      run: |
-        echo '${{ secrets.IOTLABRC }}' > ~/.iotlabrc
-    - name: Setup SSH agent
-      uses: webfactory/ssh-agent@v0.4.1
-      with:
-        ssh-private-key: ${{ secrets.IOTLAB_PRIVATE_KEY }}
-    - name: Fetch host key from IoT-LAB saclay site
-      run: |
-        IOTLAB_USER=$(cat ~/.iotlabrc | cut -f1 -d:)
-        ssh -oStrictHostKeyChecking=accept-new \
-          ${IOTLAB_USER}@saclay.iot-lab.info exit
-    - name: Run release tests
-      timeout-minutes: 350
-      run: |
-        # definition in env does not work since $GITHUB_WORKSPACE seems not to
-        # be accessible
-        export RIOTBASE="$GITHUB_WORKSPACE/RIOT"
-        TOX_ARGS=""
-        if ! echo ${{ github.event.inputs.riot_version }} | \
-              grep -q "[0-9]\{4\}.[0-9]\{2\}-RC[0-9]\+"; then
-          TOX_ARGS+="--non-RC "
-        fi
-
-        cd Release-Specs
-        BUILD_IN_DOCKER=1 \
-          DOCKER_ENV_VARS=USEMODULE \
-          $(which tox) -- ${TOX_ARGS} -m "iotlab_creds"
-    - name: junit2html and XML deploy
-      if: always()
-      run: |
-        DATE=$(date +"%Y-%m-%d-%H-%M-%S")
-        if echo ${{ github.event.inputs.riot_version }} | \
-              grep -q "[0-9]\{4\}.[0-9]\{2\}"; then
-          VER=${{ github.event.inputs.riot_version }}
-        else
-          VER=$(git -C $GITHUB_WORKSPACE/RIOT rev-parse --short HEAD)
-        fi
-        mkdir test-reports/
-        junit2html $GITHUB_WORKSPACE/Release-Specs/test-report.xml \
-          test-reports/test-report-iotlab-$VER-$DATE.html
-        cp $GITHUB_WORKSPACE/Release-Specs/test-report.xml \
-          test-reports/test-report-iotlab-$VER-$DATE.xml
-    - uses: actions/upload-artifact@v2
-      if: always()
-      with:
-        name: Test Reports
-        path: test-reports/*