diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 00000000..d123b3b1
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,14 @@
+import subprocess
+
+import pytest
+import shutil
+
+@pytest.fixture(scope="session")
+def temp_examples_dir(request, tmp_path_factory):
+    """Clone PET Examples repo to a temp dir. Return its path."""
+    pth = tmp_path_factory.mktemp("temp_dir")
+    subprocess.run(["git", "clone", "--depth", "1",
+                    "https://github.com/patnr/PET-Examples.git", pth],
+                   check=True)
+    yield pth
+    shutil.rmtree(str(pth))
diff --git a/tests/test_linear.py b/tests/test_linear.py
new file mode 100644
index 00000000..b577bbe7
--- /dev/null
+++ b/tests/test_linear.py
@@ -0,0 +1,41 @@
+import os
+import sys
+from pathlib import Path, PosixPath
+
+import numpy as np
+import subprocess
+
+# Logger (since we cannot print during testing)
+# -- there is probably a more official way to do this.
+logfile = Path.cwd() / "PET-test-log"
+with open(logfile, "w") as file:
+    pass
+def prnt(*args, **kwargs):
+    with open(logfile, "a") as file:
+        print(*args, **kwargs, file=file)
+
+
+def test_git_clone(temp_examples_dir):
+    # prnt(cwd)
+    # prnt(os.listdir(cwd))
+    assert (temp_examples_dir / "3Spot").is_dir()
+
+
+def test_mod(temp_examples_dir: PosixPath):
+    """Validate a few values of the result of the `LinearModel` example."""
+    cwd = temp_examples_dir / "LinearModel"
+    old = Path.cwd()
+
+    try:
+        os.chdir(cwd)
+        sys.path.append(str(cwd))
+        subprocess.run(["python", "write_true_and_data.py"], cwd=temp_examples_dir)
+        import run_script
+    finally:
+        os.chdir(old)
+
+    result = run_script.assimilation.ensemble.state['permx'].mean(axis=1)
+    np.testing.assert_array_almost_equal(
+        result[[1, 2, 3, -3, -2, -1]],
+        [-0.07294738, 0.00353635, -0.06393236, 0.45394362, 0.44388684, 0.37096157],
+        decimal=5)