diff --git a/.github/actions/linux/action.yaml b/.github/actions/linux/action.yaml
new file mode 100644
index 0000000..3743358
--- /dev/null
+++ b/.github/actions/linux/action.yaml
@@ -0,0 +1,18 @@
+inputs:
+  pytest-options:
+    description: "Extra options to pass to Pytest"
+    default: ''
+runs:
+  using: "composite"
+  steps:
+  - name: Install apt dependencies
+    shell: bash -l {0}
+    run: |
+      sudo apt update
+      sudo apt install xvfb libqt5x11extras5 libgl1-mesa-glx '^libxcb.*-dev'
+  - name: Install RasCAL2
+    shell: bash -l {0}
+    run: pip install .
+  - name: 
+    shell: bash -l {0}
+    run:  xvfb-run pytest -s tests/ ${{ inputs.pytest-options }} --cov=rascal2 --cov-report=term
diff --git a/.github/actions/windows-mac/action.yaml b/.github/actions/windows-mac/action.yaml
new file mode 100644
index 0000000..7d7bd0c
--- /dev/null
+++ b/.github/actions/windows-mac/action.yaml
@@ -0,0 +1,13 @@
+inputs:
+  pytest-options:
+    description: "Extra options to pass to Pytest"
+    default: ''
+runs:
+  using: "composite"
+  steps:
+  - name: Install RasCAL2
+    shell: bash -l {0}
+    run:  pip install .
+  - name: Run Pytest
+    shell: bash -l {0}
+    run:  pytest -s tests/ ${{ inputs.pytest-options }} --cov=rascal2 --cov-report=term
diff --git a/.github/workflows/integration_tests.yaml b/.github/workflows/integration_tests.yaml
index fc6f13d..113ce7c 100644
--- a/.github/workflows/integration_tests.yaml
+++ b/.github/workflows/integration_tests.yaml
@@ -2,24 +2,31 @@
 name: Integration tests
 on:
   pull_request_review:
-    types: [approved]
+    types: [submitted]
   workflow_dispatch:  # <-- can be triggered manually!
 
 jobs:
   integration-tests:
+    if: github.event.review.state == 'approved'
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-13]
-        python-version: [3.10, 3.11, 3.12]
+        python-version: ["3.10", "3.12"]
+    runs-on: ${{ matrix.os }}
     steps:
-      - name: Set up Python version ${{ matrix.version }}
-        uses: actions/setup-python@v4
+      - uses: actions/checkout@v4      
+      - name: Set up Conda environment from environment.yaml
+        uses: conda-incubator/setup-miniconda@v3
         with:
-          python-version: ${{ matrix.version }}
-      - name: Install package and requirements
-        run: |
-          pip install -r requirements.txt
-          pip install -r requirements-dev.txt
-          pip install .
-      - name: Run pytest
-        run: pytest -s tests/ --cov=rascal2 --cov-report=term
\ No newline at end of file
+          environment-file: environment.yaml
+          auto-activate-base: false
+          python-version: ${{ matrix.version }}  # this overwrites python version in environment.yaml
+      - name: Install and run tests (Linux)
+        if: runner.os == 'linux'
+        uses: ./.github/actions/linux
+      - name: Install and run tests (MacOS)
+        if: runner.os == 'macos'
+        uses: ./.github/actions/macos
+      - name: Install and run tests (Windows)
+        if: runner.os == 'windows'
+        uses: ./.github/actions/windows
diff --git a/.github/workflows/unit_tests.yaml b/.github/workflows/unit_tests.yaml
index abaa791..ee24269 100644
--- a/.github/workflows/unit_tests.yaml
+++ b/.github/workflows/unit_tests.yaml
@@ -6,6 +6,10 @@ on:
   pull_request:
     branches: [ main ]
 
+concurrency:
+  group: ${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
 jobs:
   ruff:
     runs-on: ubuntu-latest
@@ -22,6 +26,8 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-13]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
     
     steps:
       - uses: actions/checkout@v4      
@@ -30,7 +36,12 @@ jobs:
         with:
           environment-file: environment.yaml
           auto-activate-base: false
-      - name: Install RasCAL2
-        run: pip install .
-      - name: Run pytest
-        run: pytest -s tests/ -m "not slow" --cov=rascal2 --cov-report=term
+      - name: Install and run tests (Linux)
+        if: runner.os == 'linux'
+        uses: ./.github/actions/linux
+        with:
+          pytest-options: '-m "not slow"'
+      - name: Install and run tests (MacOS/Windows)
+        if: runner.os != 'linux'
+        uses: ./.github/actions/windows-mac
+
diff --git a/requirements.txt b/requirements.txt
index 44fcced..f237bce 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
 PyInstaller==6.9.0
-PyQt6==6.7.1
+PyQt6==6.7.0
 PyQt6-Qt6==6.7.2
-RATapi @ git+https://github.com/RascalSoftware/python-RAT@main
+RATapi==0.0.0.dev1