diff --git a/base-notebook/test/test_container_options.py b/base-notebook/test/test_container_options.py
index 0c4097bb..4231a5a1 100644
--- a/base-notebook/test/test_container_options.py
+++ b/base-notebook/test/test_container_options.py
@@ -23,9 +23,7 @@ def test_cli_args(container: TrackedContainer, http_client: requests.Session) ->
     logs = running_container.logs().decode("utf-8")
     LOGGER.debug(logs)
     assert "ERROR" not in logs
-    warnings = [
-        warning for warning in logs.split("\n") if warning.startswith("WARNING")
-    ]
+    warnings = TrackedContainer.get_warnings(logs)
     assert not warnings
     assert "login_submit" not in resp.text
 
@@ -48,9 +46,7 @@ def test_unsigned_ssl(
     assert "login_submit" in resp.text
     logs = running_container.logs().decode("utf-8")
     assert "ERROR" not in logs
-    warnings = [
-        warning for warning in logs.split("\n") if warning.startswith("WARNING")
-    ]
+    warnings = TrackedContainer.get_warnings(logs)
     assert not warnings
 
 
@@ -218,9 +214,7 @@ def test_group_add(container: TrackedContainer) -> None:
         group_add=["users"],  # Ensures write access to /home/jovyan
         command=["start.sh", "id"],
     )
-    warnings = [
-        warning for warning in logs.split("\n") if warning.startswith("WARNING")
-    ]
+    warnings = TrackedContainer.get_warnings(logs)
     assert len(warnings) == 1
     assert "Try setting gid=0" in warnings[0]
     assert "uid=1010 gid=1010 groups=1010,100(users)" in logs
@@ -239,9 +233,7 @@ def test_set_uid(container: TrackedContainer) -> None:
         command=["start.sh", "id"],
     )
     assert "uid=1010(jovyan) gid=0(root)" in logs
-    warnings = [
-        warning for warning in logs.split("\n") if warning.startswith("WARNING")
-    ]
+    warnings = TrackedContainer.get_warnings(logs)
     assert len(warnings) == 1
     assert "--group-add=users" in warnings[0]
 
@@ -257,9 +249,7 @@ def test_set_uid_and_nb_user(container: TrackedContainer) -> None:
         command=["start.sh", "id"],
     )
     assert "uid=1010(kitten) gid=0(root)" in logs
-    warnings = [
-        warning for warning in logs.split("\n") if warning.startswith("WARNING")
-    ]
+    warnings = TrackedContainer.get_warnings(logs)
     assert len(warnings) == 1
     assert "user is kitten but home is /home/jovyan" in warnings[0]
 
diff --git a/base-notebook/test/test_start_container.py b/base-notebook/test/test_start_container.py
index e9dc2c18..ace561ba 100644
--- a/base-notebook/test/test_start_container.py
+++ b/base-notebook/test/test_start_container.py
@@ -5,7 +5,6 @@ import logging
 from typing import Optional
 import pytest
 import requests
-import re
 import time
 
 from conftest import TrackedContainer
@@ -65,10 +64,8 @@ def test_start_notebook(
     assert "ERROR" not in logs, "ERROR(s) found in logs"
     for exp_warning in expected_warnings:
         assert exp_warning in logs, f"Expected warning {exp_warning} not found in logs"
-    warnings = re.findall(r"^WARNING", logs, flags=re.MULTILINE)
-    assert len(expected_warnings) == len(
-        warnings
-    ), "Not found the number of expected warnings in logs"
+    warnings = TrackedContainer.get_warnings(logs)
+    assert len(expected_warnings) == len(warnings)
     # checking if the server is listening
     if expected_start:
         resp = http_client.get("http://localhost:8888")
diff --git a/conftest.py b/conftest.py
index effe3720..3aca1dd5 100644
--- a/conftest.py
+++ b/conftest.py
@@ -107,6 +107,12 @@ class TrackedContainer:
         assert rv == 0 or rv["StatusCode"] == 0
         return logs
 
+    @staticmethod
+    def get_warnings(logs: str) -> list[str]:
+        return [
+            warning for warning in logs.split("\n") if warning.startswith("WARNING")
+        ]
+
     def remove(self):
         """Kills and removes the tracked docker container."""
         if self.container: