diff --git a/tests/test_k8s_util.py b/tests/test_k8s_util.py
new file mode 100644
index 0000000..8354ffe
--- /dev/null
+++ b/tests/test_k8s_util.py
@@ -0,0 +1,53 @@
+import pytest
+import kubernetes
+
+from illuminatio.k8s_util import resolve_port_from_candidates, is_numerical_port
+
+
+@pytest.mark.parametrize(
+    "pods,portname,expected_port",
+    [
+        (
+            kubernetes.client.V1PodList(
+                api_version="v1",
+                items=[
+                    kubernetes.client.V1Pod(
+                        spec=kubernetes.client.V1PodSpec(
+                            containers=[
+                                kubernetes.client.V1Container(
+                                    image="nginx",
+                                    name="myfancydeployment",
+                                    ports=[
+                                        kubernetes.client.V1ContainerPort(
+                                            name="mywronlgynamedport",
+                                            container_port=8080,
+                                            protocol="TCP",
+                                        ),
+                                        kubernetes.client.V1ContainerPort(
+                                            name="mynamedport",
+                                            container_port=80,
+                                            protocol="TCP",
+                                        ),
+                                    ],
+                                )
+                            ]
+                        )
+                    )
+                ],
+            ),
+            "mynamedport",
+            80,
+        ),
+    ],
+)
+def test_resolve_port_from_candidates(pods, portname, expected_port):
+    actual_port = resolve_port_from_candidates(pods, portname)
+    assert actual_port == expected_port
+
+
+@pytest.mark.parametrize(
+    "port,expected", [("80", True), ("*", False), (80, True), ("my-named-port", False)],
+)
+def test_is_numerical_port(port, expected):
+    actual = is_numerical_port(port)
+    assert actual == expected