diff --git a/.github/workflows/unit-tests.yaml b/.github/workflows/unit-tests.yaml
index 88130cd03..6511b37cc 100644
--- a/.github/workflows/unit-tests.yaml
+++ b/.github/workflows/unit-tests.yaml
@@ -30,11 +30,11 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: install dependencies
-        run: uv sync
+        run: uv sync --group ci
 
       - name: Install test-only dependencies (Python 3.9 and 3.13)
         if: matrix.python-version == '3.9' || matrix.python-version == '3.13'
-        run: uv sync --group tests
+        run: uv sync --group ci --group tests
 
       - name: Unit tests
-        run: uv run pytest tests/
+        run: uv run pytest tests/ -n auto --dist loadfile
diff --git a/.github/workflows/windows-unit-tests.yml b/.github/workflows/windows-unit-tests.yml
index 20b2da52e..f16d7871a 100644
--- a/.github/workflows/windows-unit-tests.yml
+++ b/.github/workflows/windows-unit-tests.yml
@@ -28,7 +28,7 @@ jobs:
           python-version: "3.13"
 
       - name: install dependencies
-        run: uv sync
+        run: uv sync --group ci
 
       - name: Unit tests
-        run: uv run pytest tests/
+        run: uv run pytest tests/ -n auto --dist loadfile
diff --git a/pyproject.toml b/pyproject.toml
index 82e4f21a6..daf6d3ab8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -81,6 +81,9 @@ dev = [
     "uv>=0.6.2",
     "pre-commit>=4.2.0,<5",
 ]
+ci = [
+    "pytest-xdist>=3.5.0",
+]
 tests = [
     "black>=25.9.0",
     "jax>=0.4.30",