diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 26cc61cbd..67333c21d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -57,7 +57,7 @@ jobs:
         k3s-channel:
           # Available channels: https://github.com/k3s-io/k3s/blob/HEAD/channel.yaml
           # Don't use "latest", instead bump it using a PR so we know when a new version breaks BinderHub
-          - v1.29
+          - v1.30
         test:
           - main
           - auth
@@ -69,7 +69,7 @@ jobs:
           # which isn't documented anywhere, but is currently at 3.5.0. We also
           # test with the latest k8s and helm versions.
           #
-          - k3s-channel: v1.23
+          - k3s-channel: v1.28
             helm-version: v3.5.0
             test: helm
             test-variation: dind
diff --git a/binderhub/events.py b/binderhub/events.py
index a2a071140..02fa730e6 100644
--- a/binderhub/events.py
+++ b/binderhub/events.py
@@ -12,14 +12,17 @@
 from traitlets.config import Configurable
 
 
-def _skip_message(record, **kwargs):
+def _skip_fields(record, **kwargs):
     """
-    Remove 'message' from log record.
+    Remove unwanted fields from log record.
 
-    It is always emitted with 'null', and we do not want it,
-    since we are always emitting events only
+    message: always emitted with 'null', and we do not want it,
+      since we are always emitting events only
+    taskName:
     """
     del record["message"]
+    if "taskName" in record:
+        del record["taskName"]
     return json.dumps(record, **kwargs)
 
 
@@ -49,7 +52,7 @@ def __init__(self, *args, **kwargs):
 
         if self.handlers_maker:
             self.handlers = self.handlers_maker(self)
-            formatter = jsonlogger.JsonFormatter(json_serializer=_skip_message)
+            formatter = jsonlogger.JsonFormatter(json_serializer=_skip_fields)
             for handler in self.handlers:
                 handler.setFormatter(formatter)
                 self.log.addHandler(handler)
diff --git a/binderhub/tests/test_build.py b/binderhub/tests/test_build.py
index 3f9fca503..029ac4ba9 100644
--- a/binderhub/tests/test_build.py
+++ b/binderhub/tests/test_build.py
@@ -21,7 +21,7 @@
 
 # We have optimized this slow test, for more information, see the README of
 # https://github.com/binderhub-ci-repos/minimal-dockerfile.
-@pytest.mark.asyncio(timeout=900)
+@pytest.mark.timeout(900)
 @pytest.mark.parametrize(
     "slug",
     [
@@ -102,7 +102,7 @@ async def test_build(app, needs_build, needs_launch, always_build, slug, pytestc
     stop.raise_for_status()
 
 
-@pytest.mark.asyncio(timeout=900)
+@pytest.mark.timeout(900)
 @pytest.mark.parametrize(
     "app,build_only_query_param",
     [
@@ -152,7 +152,7 @@ async def test_build_only(app, build_only_query_param, needs_build):
     assert final["phase"] == "ready"
 
 
-@pytest.mark.asyncio(timeout=120)
+@pytest.mark.timeout(120)
 @pytest.mark.remote
 async def test_build_fail(app, needs_build, needs_launch, always_build):
     """
@@ -176,7 +176,7 @@ async def test_build_fail(app, needs_build, needs_launch, always_build):
     assert failed_events > 0, "Should have seen phase 'failed'"
 
 
-@pytest.mark.asyncio(timeout=120)
+@pytest.mark.timeout(120)
 @pytest.mark.parametrize(
     "app,build_only_query_param,expected_error_msg",
     [
@@ -485,7 +485,7 @@ async def test_local_repo2docker_build():
     assert docker_client.images.get(name)
 
 
-@pytest.mark.asyncio(timeout=20)
+@pytest.mark.timeout(20)
 async def test_local_repo2docker_build_stop(io_loop):
     q = Queue()
     # We need a slow build here so that we can interrupt it, so pick a large repo that
diff --git a/helm-chart/binderhub/Chart.yaml b/helm-chart/binderhub/Chart.yaml
index 66b24727f..c04c1b7d4 100644
--- a/helm-chart/binderhub/Chart.yaml
+++ b/helm-chart/binderhub/Chart.yaml
@@ -12,7 +12,7 @@ dependencies:
   #            and run "./dependencies freeze --upgrade".
   #
   - name: jupyterhub
-    version: "3.3.7"
+    version: "4.0.0"
     repository: "https://jupyterhub.github.io/helm-chart"
 description: |-
   BinderHub is like a JupyterHub that automatically builds environments for the
@@ -22,7 +22,7 @@ keywords: [jupyter, jupyterhub, binderhub]
 home: https://binderhub.readthedocs.io/en/latest/
 sources: [https://github.com/jupyterhub/binderhub]
 icon: https://jupyterhub.github.io/helm-chart/images/hublogo.svg
-kubeVersion: ">=1.23.0-0"
+kubeVersion: ">=1.28.0-0"
 maintainers:
   # Since it is a requirement of Artifact Hub to have specific maintainers
   # listed, we have added some below, but in practice the entire JupyterHub team
diff --git a/helm-chart/binderhub/values.yaml b/helm-chart/binderhub/values.yaml
index e11c7237e..bd1f4c6dd 100644
--- a/helm-chart/binderhub/values.yaml
+++ b/helm-chart/binderhub/values.yaml
@@ -72,7 +72,7 @@ jupyterhub:
   hub:
     config:
       JupyterHub:
-        authenticator_class: nullauthenticator.NullAuthenticator
+        authenticator_class: "null"
       BinderSpawner:
         auth_enabled: false
     loadRoles:
diff --git a/tools/templates/lint-and-validate-values.yaml b/tools/templates/lint-and-validate-values.yaml
index 4b2d0ea15..92af3d540 100644
--- a/tools/templates/lint-and-validate-values.yaml
+++ b/tools/templates/lint-and-validate-values.yaml
@@ -56,7 +56,7 @@ jupyterhub:
   hub:
     config:
       JupyterHub:
-        authenticator_class: nullauthenticator.NullAuthenticator
+        authenticator_class: "null"
     extraConfig:
       hub-test-config: |
         dummy jupyterhub python code...