diff --git a/all-spark-notebook/test/test_spark_notebooks.py b/all-spark-notebook/test/test_spark_notebooks.py
index 9879a438..a94279e7 100644
--- a/all-spark-notebook/test/test_spark_notebooks.py
+++ b/all-spark-notebook/test/test_spark_notebooks.py
@@ -30,14 +30,11 @@ def test_nbconvert(container: TrackedContainer, test_file: str) -> None:
         + f"--output-dir {output_dir} "
         + f"--execute {cont_data_dir}/{test_file}.ipynb"
     )
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=timeout_ms / 10 + 10,
         volumes={str(host_data_dir): {"bind": cont_data_dir, "mode": "ro"}},
         tty=True,
         command=["start.sh", "bash", "-c", command],
     )
-    rv = c.wait(timeout=timeout_ms / 10 + 10)
-    logs = c.logs(stdout=True).decode("utf-8")
-    LOGGER.debug(logs)
-    assert rv == 0 or rv["StatusCode"] == 0, f"Command {command} failed"
     expected_file = f"{output_dir}/{test_file}.md"
     assert expected_file in logs, f"Expected file {expected_file} not generated"
diff --git a/base-notebook/test/test_container_options.py b/base-notebook/test/test_container_options.py
index 2c32d335..0c4097bb 100644
--- a/base-notebook/test/test_container_options.py
+++ b/base-notebook/test/test_container_options.py
@@ -1,5 +1,6 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
+import pathlib
 import time
 import logging
 
@@ -14,10 +15,12 @@ LOGGER = logging.getLogger(__name__)
 def test_cli_args(container: TrackedContainer, http_client: requests.Session) -> None:
     """Container should respect notebook server command line args
     (e.g., disabling token security)"""
-    c = container.run(command=["start-notebook.sh", "--NotebookApp.token=''"])
+    running_container = container.run_detached(
+        command=["start-notebook.sh", "--NotebookApp.token=''"]
+    )
     resp = http_client.get("http://localhost:8888")
     resp.raise_for_status()
-    logs = c.logs(stdout=True).decode("utf-8")
+    logs = running_container.logs().decode("utf-8")
     LOGGER.debug(logs)
     assert "ERROR" not in logs
     warnings = [
@@ -34,7 +37,7 @@ def test_unsigned_ssl(
     """Container should generate a self-signed SSL certificate
     and notebook server should use it to enable HTTPS.
     """
-    c = container.run(environment=["GEN_CERT=yes"])
+    running_container = container.run_detached(environment=["GEN_CERT=yes"])
     # NOTE: The requests.Session backing the http_client fixture does not retry
     # properly while the server is booting up. An SSL handshake error seems to
     # abort the retry logic. Forcing a long sleep for the moment until I have
@@ -43,7 +46,7 @@ def test_unsigned_ssl(
     resp = http_client.get("https://localhost:8888", verify=False)
     resp.raise_for_status()
     assert "login_submit" in resp.text
-    logs = c.logs(stdout=True).decode("utf-8")
+    logs = running_container.logs().decode("utf-8")
     assert "ERROR" not in logs
     warnings = [
         warning for warning in logs.split("\n") if warning.startswith("WARNING")
@@ -53,34 +56,25 @@ def test_unsigned_ssl(
 
 def test_uid_change(container: TrackedContainer) -> None:
     """Container should change the UID of the default user."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=120,  # usermod is slow so give it some time
         tty=True,
         user="root",
         environment=["NB_UID=1010"],
         command=["start.sh", "bash", "-c", "id && touch /opt/conda/test-file"],
     )
-    # usermod is slow so give it some time
-    rv = c.wait(timeout=120)
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
-    assert rv == 0 or rv["StatusCode"] == 0
-    assert "uid=1010(jovyan)" in c.logs(stdout=True).decode("utf-8")
+    assert "uid=1010(jovyan)" in logs
 
 
 def test_gid_change(container: TrackedContainer) -> None:
     """Container should change the GID of the default user."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=10,
         tty=True,
         user="root",
         environment=["NB_GID=110"],
         command=["start.sh", "id"],
     )
-    rv = c.wait(timeout=10)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
     assert "gid=110(jovyan)" in logs
     assert "groups=110(jovyan),100(users)" in logs
 
@@ -88,7 +82,7 @@ def test_gid_change(container: TrackedContainer) -> None:
 def test_nb_user_change(container: TrackedContainer) -> None:
     """Container should change the user name (`NB_USER`) of the default user."""
     nb_user = "nayvoj"
-    running_container = container.run(
+    running_container = container.run_detached(
         tty=True,
         user="root",
         environment=[f"NB_USER={nb_user}", "CHOWN_HOME=yes"],
@@ -99,7 +93,7 @@ def test_nb_user_change(container: TrackedContainer) -> None:
     # container sleeps forever.
     time.sleep(10)
     LOGGER.info(f"Checking if the user is changed to {nb_user} by the start script ...")
-    output = running_container.logs(stdout=True).decode("utf-8")
+    output = running_container.logs().decode("utf-8")
     assert "ERROR" not in output
     assert "WARNING" not in output
     assert (
@@ -137,7 +131,8 @@ def test_nb_user_change(container: TrackedContainer) -> None:
 def test_chown_extra(container: TrackedContainer) -> None:
     """Container should change the UID/GID of a comma separated
     CHOWN_EXTRA list of folders."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=120,  # chown is slow so give it some time
         tty=True,
         user="root",
         environment=[
@@ -153,12 +148,6 @@ def test_chown_extra(container: TrackedContainer) -> None:
             "stat -c '%n:%u:%g' /home/jovyan/.bashrc /opt/conda/bin/jupyter",
         ],
     )
-    # chown is slow so give it some time
-    rv = c.wait(timeout=120)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
     assert "/home/jovyan/.bashrc:1010:101" in logs
     assert "/opt/conda/bin/jupyter:1010:101" in logs
 
@@ -166,7 +155,8 @@ def test_chown_extra(container: TrackedContainer) -> None:
 def test_chown_home(container: TrackedContainer) -> None:
     """Container should change the NB_USER home directory owner and
     group to the current value of NB_UID and NB_GID."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=120,  # chown is slow so give it some time
         tty=True,
         user="root",
         environment=[
@@ -178,58 +168,41 @@ def test_chown_home(container: TrackedContainer) -> None:
         ],
         command=["start.sh", "bash", "-c", "stat -c '%n:%u:%g' /home/kitten/.bashrc"],
     )
-    rv = c.wait(timeout=120)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
     assert "/home/kitten/.bashrc:1010:101" in logs
 
 
 def test_sudo(container: TrackedContainer) -> None:
     """Container should grant passwordless sudo to the default user."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=10,
         tty=True,
         user="root",
         environment=["GRANT_SUDO=yes"],
         command=["start.sh", "sudo", "id"],
     )
-    rv = c.wait(timeout=10)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
     assert "uid=0(root)" in logs
 
 
 def test_sudo_path(container: TrackedContainer) -> None:
     """Container should include /opt/conda/bin in the sudo secure_path."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=10,
         tty=True,
         user="root",
         environment=["GRANT_SUDO=yes"],
         command=["start.sh", "sudo", "which", "jupyter"],
     )
-    rv = c.wait(timeout=10)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
     assert logs.rstrip().endswith("/opt/conda/bin/jupyter")
 
 
 def test_sudo_path_without_grant(container: TrackedContainer) -> None:
     """Container should include /opt/conda/bin in the sudo secure_path."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=10,
         tty=True,
         user="root",
         command=["start.sh", "which", "jupyter"],
     )
-    rv = c.wait(timeout=10)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
     assert logs.rstrip().endswith("/opt/conda/bin/jupyter")
 
 
@@ -238,15 +211,13 @@ def test_group_add(container: TrackedContainer) -> None:
     group. It won't be possible to modify /etc/passwd since gid is nonzero, so
     additionally verify that setting gid=0 is suggested in a warning.
     """
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=5,
+        no_warnings=False,
         user="1010:1010",
         group_add=["users"],  # Ensures write access to /home/jovyan
         command=["start.sh", "id"],
     )
-    rv = c.wait(timeout=5)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
     warnings = [
         warning for warning in logs.split("\n") if warning.startswith("WARNING")
     ]
@@ -261,14 +232,12 @@ def test_set_uid(container: TrackedContainer) -> None:
     Additionally verify that "--group-add=users" is suggested in a warning to restore
     write access.
     """
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=5,
+        no_warnings=False,
         user="1010",
         command=["start.sh", "id"],
     )
-    rv = c.wait(timeout=5)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
     assert "uid=1010(jovyan) gid=0(root)" in logs
     warnings = [
         warning for warning in logs.split("\n") if warning.startswith("WARNING")
@@ -279,16 +248,14 @@ def test_set_uid(container: TrackedContainer) -> None:
 
 def test_set_uid_and_nb_user(container: TrackedContainer) -> None:
     """Container should run with the specified uid and NB_USER."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=5,
+        no_warnings=False,
         user="1010",
         environment=["NB_USER=kitten"],
         group_add=["users"],  # Ensures write access to /home/jovyan
         command=["start.sh", "id"],
     )
-    rv = c.wait(timeout=5)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
     assert "uid=1010(kitten) gid=0(root)" in logs
     warnings = [
         warning for warning in logs.split("\n") if warning.startswith("WARNING")
@@ -297,7 +264,9 @@ def test_set_uid_and_nb_user(container: TrackedContainer) -> None:
     assert "user is kitten but home is /home/jovyan" in warnings[0]
 
 
-def test_container_not_delete_bind_mount(container: TrackedContainer, tmp_path) -> None:
+def test_container_not_delete_bind_mount(
+    container: TrackedContainer, tmp_path: pathlib.Path
+) -> None:
     """Container should not delete host system files when using the (docker)
     -v bind mount flag and mapping to /home/jovyan.
     """
@@ -306,7 +275,8 @@ def test_container_not_delete_bind_mount(container: TrackedContainer, tmp_path)
     p = d / "foo.txt"
     p.write_text("some-content")
 
-    c = container.run(
+    container.run_and_wait(
+        timeout=5,
         tty=True,
         user="root",
         working_dir="/home/",
@@ -317,11 +287,6 @@ def test_container_not_delete_bind_mount(container: TrackedContainer, tmp_path)
         volumes={d: {"bind": "/home/jovyan/data", "mode": "rw"}},
         command=["start.sh", "ls"],
     )
-    rv = c.wait(timeout=5)
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
-    assert rv == 0 or rv["StatusCode"] == 0
     assert p.read_text() == "some-content"
     assert len(list(tmp_path.iterdir())) == 1
 
@@ -333,7 +298,8 @@ def test_jupyter_env_vars_to_unset_as_root(
     """Environment variables names listed in JUPYTER_ENV_VARS_TO_UNSET
     should be unset in the final environment."""
     root_args = {"user": "root"} if enable_root else {}
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=10,
         tty=True,
         environment=[
             "JUPYTER_ENV_VARS_TO_UNSET=SECRET_ANIMAL,UNUSED_ENV,SECRET_FRUIT",
@@ -349,9 +315,4 @@ def test_jupyter_env_vars_to_unset_as_root(
         ],
         **root_args,
     )
-    rv = c.wait(timeout=10)
-    assert rv == 0 or rv["StatusCode"] == 0
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
     assert "I like bananas and stuff, and love to keep secrets!" in logs
diff --git a/base-notebook/test/test_package_managers.py b/base-notebook/test/test_package_managers.py
index 6d06dedd..910baed9 100644
--- a/base-notebook/test/test_package_managers.py
+++ b/base-notebook/test/test_package_managers.py
@@ -26,15 +26,8 @@ def test_package_manager(
     LOGGER.info(
         f"Test that the package manager {package_manager} is working properly ..."
     )
-    c = container.run(
+    container.run_and_wait(
+        timeout=5,
         tty=True,
         command=["start.sh", "bash", "-c", f"{package_manager} {version_arg}"],
     )
-    rv = c.wait(timeout=5)
-    logs = c.logs(stdout=True).decode("utf-8")
-    LOGGER.debug(logs)
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
-    assert (
-        rv == 0 or rv["StatusCode"] == 0
-    ), f"Package manager {package_manager} not working"
diff --git a/base-notebook/test/test_pandoc.py b/base-notebook/test/test_pandoc.py
index fa2cfa39..e0909289 100644
--- a/base-notebook/test/test_pandoc.py
+++ b/base-notebook/test/test_pandoc.py
@@ -10,13 +10,9 @@ LOGGER = logging.getLogger(__name__)
 
 def test_pandoc(container: TrackedContainer) -> None:
     """Pandoc shall be able to convert MD to HTML."""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=10,
         tty=True,
         command=["start.sh", "bash", "-c", 'echo "**BOLD**" | pandoc'],
     )
-    c.wait(timeout=10)
-    logs = c.logs(stdout=True).decode("utf-8")
-    assert "ERROR" not in logs
-    assert "WARNING" not in logs
-    LOGGER.debug(logs)
     assert "<p><strong>BOLD</strong></p>" in logs
diff --git a/base-notebook/test/test_python.py b/base-notebook/test/test_python.py
index 5ba6aaf8..31f92b04 100644
--- a/base-notebook/test/test_python.py
+++ b/base-notebook/test/test_python.py
@@ -14,15 +14,12 @@ def test_python_version(
 ) -> None:
     """Check that python version is lower than the next version"""
     LOGGER.info(f"Checking that python version is lower than {python_next_version}")
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=5,
         tty=True,
-        command=["start.sh"],
+        command=["start.sh", "python", "--version"],
     )
-    cmd = c.exec_run("python --version")
-    output = cmd.output.decode("utf-8")
-    assert "ERROR" not in output
-    assert "WARNING" not in output
-    actual_python_version = version.parse(output.split()[1])
+    actual_python_version = version.parse(logs.split()[1])
     assert actual_python_version < version.parse(
         python_next_version
     ), f"Python version shall be lower than {python_next_version}"
diff --git a/base-notebook/test/test_start_container.py b/base-notebook/test/test_start_container.py
index fcc09f5e..e9dc2c18 100644
--- a/base-notebook/test/test_start_container.py
+++ b/base-notebook/test/test_start_container.py
@@ -48,14 +48,14 @@ def test_start_notebook(
     LOGGER.info(
         f"Test that the start-notebook launches the {expected_command} server from the env {env} ..."
     )
-    c = container.run(
+    running_container = container.run_detached(
         tty=True,
         environment=env,
         command=["start-notebook.sh"],
     )
     # sleeping some time to let the server start
     time.sleep(3)
-    logs = c.logs(stdout=True).decode("utf-8")
+    logs = running_container.logs().decode("utf-8")
     LOGGER.debug(logs)
     # checking that the expected command is launched
     assert (
@@ -84,12 +84,12 @@ def test_tini_entrypoint(
     https://superuser.com/questions/632979/if-i-know-the-pid-number-of-a-process-how-can-i-get-its-name
     """
     LOGGER.info(f"Test that {command} is launched as PID {pid} ...")
-    c = container.run(
+    running_container = container.run_detached(
         tty=True,
         command=["start.sh"],
     )
     # Select the PID 1 and get the corresponding command
-    cmd = c.exec_run(f"ps -p {pid} -o comm=")
+    cmd = running_container.exec_run(f"ps -p {pid} -o comm=")
     output = cmd.output.decode("utf-8").strip("\n")
     assert "ERROR" not in output
     assert "WARNING" not in output
diff --git a/conftest.py b/conftest.py
index 07f350a8..9c5e98cc 100644
--- a/conftest.py
+++ b/conftest.py
@@ -5,6 +5,7 @@ import logging
 import typing
 
 import docker
+from docker.models.containers import Container
 import pytest
 import requests
 
@@ -59,7 +60,7 @@ class TrackedContainer:
         self.image_name = image_name
         self.kwargs = kwargs
 
-    def run(self, **kwargs: typing.Any):
+    def run_detached(self, **kwargs: typing.Any) -> Container:
         """Runs a docker container using the preconfigured image name
         and a mix of the preconfigured container options and those passed
         to this method.
@@ -85,6 +86,24 @@ class TrackedContainer:
         )
         return self.container
 
+    def run_and_wait(
+        self,
+        timeout: int,
+        no_warnings: bool = True,
+        no_errors: bool = True,
+        **kwargs: typing.Any,
+    ) -> str:
+        running_container = self.run_and_wait(**kwargs)
+        rv = running_container.wait(timeout=timeout)
+        logs = running_container.logs().decode("utf-8")
+        LOGGER.debug(logs)
+        if no_warnings:
+            assert "WARNING" not in logs
+        if no_errors:
+            assert "ERROR" not in logs
+        assert rv == 0 or rv["StatusCode"] == 0
+        return logs
+
     def remove(self):
         """Kills and removes the tracked docker container."""
         if self.container:
diff --git a/datascience-notebook/test/test_julia.py b/datascience-notebook/test/test_julia.py
index d1a79aa6..cb9411e0 100644
--- a/datascience-notebook/test/test_julia.py
+++ b/datascience-notebook/test/test_julia.py
@@ -10,7 +10,7 @@ LOGGER = logging.getLogger(__name__)
 def test_julia(container: TrackedContainer) -> None:
     """Basic julia test"""
     LOGGER.info("Test that julia is correctly installed ...")
-    running_container = container.run(
+    running_container = container.run_detached(
         tty=True,
         command=["start.sh", "bash", "-c", "sleep infinity"],
     )
diff --git a/minimal-notebook/test/test_inkscape.py b/minimal-notebook/test/test_inkscape.py
index 451ef9b5..f3d7a6d8 100644
--- a/minimal-notebook/test/test_inkscape.py
+++ b/minimal-notebook/test/test_inkscape.py
@@ -11,11 +11,9 @@ LOGGER = logging.getLogger(__name__)
 def test_inkscape(container: TrackedContainer) -> None:
     """Inkscape shall be installed to be able to convert SVG files."""
     LOGGER.info("Test that inkscape is working by printing its version ...")
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=10,
         tty=True,
         command=["start.sh", "bash", "-c", "inkscape --version"],
     )
-    c.wait(timeout=10)
-    logs = c.logs(stdout=True).decode("utf-8")
-    LOGGER.debug(logs)
     assert "Inkscape" in logs, "Inkscape not installed or not working"
diff --git a/minimal-notebook/test/test_nbconvert.py b/minimal-notebook/test/test_nbconvert.py
index 755c7f5c..9dbe0d2f 100644
--- a/minimal-notebook/test/test_nbconvert.py
+++ b/minimal-notebook/test/test_nbconvert.py
@@ -6,6 +6,8 @@ import logging
 import pytest
 from pathlib import Path
 
+from conftest import TrackedContainer
+
 LOGGER = logging.getLogger(__name__)
 THIS_DIR = Path(__file__).parent.resolve()
 
@@ -19,7 +21,9 @@ THIS_DIR = Path(__file__).parent.resolve()
         ("notebook_svg", "html"),
     ],
 )
-def test_nbconvert(container, test_file: str, output_format: str) -> None:
+def test_nbconvert(
+    container: TrackedContainer, test_file: str, output_format: str
+) -> None:
     """Check if nbconvert is able to convert a notebook file"""
     host_data_dir = THIS_DIR / "data"
     cont_data_dir = "/home/jovyan/data"
@@ -28,14 +32,11 @@ def test_nbconvert(container, test_file: str, output_format: str) -> None:
         f"Test that the example notebook {test_file} can be converted to {output_format} ..."
     )
     command = f"jupyter nbconvert {cont_data_dir}/{test_file}.ipynb --output-dir {output_dir} --to {output_format}"
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=30,
         volumes={str(host_data_dir): {"bind": cont_data_dir, "mode": "ro"}},
         tty=True,
         command=["start.sh", "bash", "-c", command],
     )
-    rv = c.wait(timeout=30)
-    logs = c.logs(stdout=True).decode("utf-8")
-    LOGGER.debug(logs)
-    assert rv == 0 or rv["StatusCode"] == 0, f"Command {command} failed"
     expected_file = f"{output_dir}/{test_file}.{output_format}"
     assert expected_file in logs, f"Expected file {expected_file} not generated"
diff --git a/pyspark-notebook/test/test_spark.py b/pyspark-notebook/test/test_spark.py
index 66abeb9a..56b8c0e2 100644
--- a/pyspark-notebook/test/test_spark.py
+++ b/pyspark-notebook/test/test_spark.py
@@ -10,11 +10,9 @@ LOGGER = logging.getLogger(__name__)
 
 def test_spark_shell(container: TrackedContainer) -> None:
     """Checking if Spark (spark-shell) is running properly"""
-    c = container.run(
+    logs = container.run_and_wait(
+        timeout=60,
         tty=True,
         command=["start.sh", "bash", "-c", 'spark-shell <<< "1+1"'],
     )
-    c.wait(timeout=60)
-    logs = c.logs(stdout=True).decode("utf-8")
-    LOGGER.debug(logs)
     assert "res0: Int = 2" in logs, "spark-shell does not work"
diff --git a/scipy-notebook/test/test_extensions.py b/scipy-notebook/test/test_extensions.py
index 386fe4f6..0d632989 100644
--- a/scipy-notebook/test/test_extensions.py
+++ b/scipy-notebook/test/test_extensions.py
@@ -27,11 +27,8 @@ def test_check_extension(container: TrackedContainer, extension: str) -> None:
 
     """
     LOGGER.info(f"Checking the extension: {extension} ...")
-    c = container.run(
+    container.run_and_wait(
+        timeout=10,
         tty=True,
         command=["start.sh", "jupyter", "labextension", "check", extension],
     )
-    rv = c.wait(timeout=10)
-    logs = c.logs(stdout=True).decode("utf-8")
-    LOGGER.debug(logs)
-    assert rv == 0 or rv["StatusCode"] == 0, f"Extension {extension} check failed"
diff --git a/scipy-notebook/test/test_matplotlib.py b/scipy-notebook/test/test_matplotlib.py
index 10229df7..54d2b812 100644
--- a/scipy-notebook/test/test_matplotlib.py
+++ b/scipy-notebook/test/test_matplotlib.py
@@ -40,7 +40,7 @@ def test_matplotlib(
     output_dir = "/tmp"
     LOGGER.info(description)
     command = "sleep infinity"
-    running_container = container.run(
+    running_container = container.run_detached(
         volumes={str(host_data_dir): {"bind": cont_data_dir, "mode": "ro"}},
         tty=True,
         command=["start.sh", "bash", "-c", command],
diff --git a/tagging/docker_runner.py b/tagging/docker_runner.py
index 1419fd96..360c61a5 100644
--- a/tagging/docker_runner.py
+++ b/tagging/docker_runner.py
@@ -1,6 +1,8 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
+from typing import Optional
 import docker
+from docker.models.containers import Container
 import logging
 
 
@@ -14,12 +16,12 @@ class DockerRunner:
         docker_client=docker.from_env(),
         command: str = "sleep infinity",
     ):
-        self.container = None
-        self.image_name = image_name
-        self.command = command
-        self.docker_client = docker_client
+        self.container: Optional[Container] = None
+        self.image_name: str = image_name
+        self.command: str = command
+        self.docker_client: docker.DockerClient = docker_client
 
-    def __enter__(self):
+    def __enter__(self) -> Container:
         LOGGER.info(f"Creating container for image {self.image_name} ...")
         self.container = self.docker_client.containers.run(
             image=self.image_name,
@@ -29,14 +31,16 @@ class DockerRunner:
         LOGGER.info(f"Container {self.container.name} created")
         return self.container
 
-    def __exit__(self, exc_type, exc_value, traceback):
+    def __exit__(self, exc_type, exc_value, traceback) -> None:
         LOGGER.info(f"Removing container {self.container.name} ...")
         if self.container:
             self.container.remove(force=True)
             LOGGER.info(f"Container {self.container.name} removed")
 
     @staticmethod
-    def run_simple_command(container, cmd: str, print_result: bool = True):
+    def run_simple_command(
+        container: Container, cmd: str, print_result: bool = True
+    ) -> str:
         LOGGER.info(f"Running cmd: '{cmd}' on container: {container}")
         out = container.exec_run(cmd)
         result = out.output.decode("utf-8").rstrip()
diff --git a/test/package_helper.py b/test/package_helper.py
index b9d9ae8d..c44b6c7d 100644
--- a/test/package_helper.py
+++ b/test/package_helper.py
@@ -50,7 +50,7 @@ class CondaPackageHelper:
     def start_container(container: TrackedContainer):
         """Start the TrackedContainer and return an instance of a running container"""
         LOGGER.info(f"Starting container {container.image_name} ...")
-        return container.run(
+        return container.run_detached(
             tty=True,
             command=["start.sh", "bash", "-c", "sleep infinity"],
         )
diff --git a/test/test_notebook.py b/test/test_notebook.py
index 4794cc5f..bc0181da 100644
--- a/test/test_notebook.py
+++ b/test/test_notebook.py
@@ -10,7 +10,7 @@ def test_secured_server(
     container: TrackedContainer, http_client: requests.Session
 ) -> None:
     """Notebook server should eventually request user login."""
-    container.run()
+    container.run_detached()
     resp = http_client.get("http://localhost:8888")
     resp.raise_for_status()
     assert "login_submit" in resp.text, "User login not requested"
diff --git a/test/test_units.py b/test/test_units.py
index 456d03e9..d9ed5329 100644
--- a/test/test_units.py
+++ b/test/test_units.py
@@ -27,12 +27,9 @@ def test_units(container: TrackedContainer) -> None:
         test_file_name = test_file.name
         LOGGER.info(f"Running unit test: {test_file_name}")
 
-        c = container.run(
+        container.run_and_wait(
+            timeout=30,
             volumes={str(host_data_dir): {"bind": cont_data_dir, "mode": "ro"}},
             tty=True,
             command=["start.sh", "python", f"{cont_data_dir}/{test_file_name}"],
         )
-        rv = c.wait(timeout=30)
-        logs = c.logs(stdout=True).decode("utf-8")
-        LOGGER.debug(logs)
-        assert rv == 0 or rv["StatusCode"] == 0