diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 8622555..c703bce 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -6,39 +6,24 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.12", "3.11", "3.10", "3.9", "3.8"]
-        plone-version: ["6.0", "5.2"]
+        python-version: ["3.13", "3.12", "3.11", "3.10", "3.9"]
+        plone-version: ["6.1", "6.0"]
         exclude:
-          - python-version: 3.12
-            plone-version: 5.2
-          - python-version: 3.11
-            plone-version: 5.2
-          - python-version: 3.10
-            plone-version: 5.2
           - python-version: 3.9
-            plone-version: 5.2
+            plone-version: 6.1
     steps:
       # git checkout
       - uses: actions/checkout@v2
 
       # python setup
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
           cache: "pip"
-
-      # python cache
-      - uses: actions/cache@v1
-        with:
-          path: ~/.cache/pip
-          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
-          restore-keys: |
-            ${{ runner.os }}-pip-
+          cache-dependency-path: "**/requirements.txt"
 
       # python install
-      - run: pip install virtualenv
-      - run: pip install wheel
       - name: pip install
         run: pip install -r requirements-${{ matrix.plone-version }}.txt
 
diff --git a/.meta.toml b/.meta.toml
index 2ca393b..d870133 100644
--- a/.meta.toml
+++ b/.meta.toml
@@ -14,4 +14,4 @@ jobs = [
     ]
 
 [pyproject]
-dependencies_ignores = "['plone.app.redirector']"
+dependencies_ignores = "['plone.app.layout', 'plone.app.redirector', 'plone.base', 'Products.CMFPlone']"
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index d63a1c8..7be8a0b 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -66,7 +66,7 @@ repos:
     hooks:
     -   id: pyroma
 -   repo: https://github.com/mgedmin/check-python-versions
-    rev: "0.22.0"
+    rev: "0.22.1"
     hooks:
     -   id: check-python-versions
         args: ['--only', 'setup.py,pyproject.toml']
diff --git a/Makefile b/Makefile
index e1eb2a8..4a77f7b 100644
--- a/Makefile
+++ b/Makefile
@@ -32,29 +32,6 @@ bin/buildout: bin/pip
 bin/python bin/pip:
 	python$(version) -m venv . || virtualenv --python=python$(version) .
 
-py2:
-	virtualenv --python=python2 .
-	bin/pip install --upgrade pip
-	bin/pip install -r requirements.txt
-
-.PHONY: Build Plone 5.2 with Python 2
-build-plone-5.2-py: py2  ## Build Plone 5.2 with Python 2
-	bin/pip install --upgrade pip
-	bin/pip install -r requirements.txt
-	bin/buildout -c plone-5.2.x.cfg
-
-.PHONY: Build Plone 5.2
-build-plone-5.2: .installed.cfg  ## Build Plone 5.2
-	bin/pip install --upgrade pip
-	bin/pip install -r requirements.txt
-	bin/buildout -c plone-5.2.x.cfg
-
-.PHONY: Build Plone 5.2 Performance
-build-plone-5.2-performance: .installed.cfg  ## Build Plone 5.2
-	bin/pip install --upgrade pip
-	bin/pip install -r requirements.txt
-	bin/buildout -c plone-5.2.x-performance.cfg
-
 build-plone-6.0:  ## Build Plone 6.0
 	python$(version) -m venv .
 	bin/pip install --upgrade pip
diff --git a/README.rst b/README.rst
index f6923eb..021f77a 100644
--- a/README.rst
+++ b/README.rst
@@ -180,7 +180,7 @@ Named services can be registered by providing a 'name' attribute in the service
   <plone:service
     method="GET"
     accept="application/json"
-    for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+    for="plone.base.interfaces.IPloneSiteRoot"
     factory=".service.Search"
     name="search"
     permission="zope2.View"
@@ -256,7 +256,7 @@ defines a policy for the site root.
 .. code-block:: XML
 
   <plone:CORSPolicy
-    for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+    for="plone.base.interfaces.IPloneSiteRoot"
     layer="myproduct.interfaces.IMyBrowserLayer"
     allow_origin="*"
     allow_methods="GET"
@@ -315,6 +315,8 @@ and then running "bin/buildout"
 Plone/Python Support
 --------------------
 
+plone.rest 5.x.x supports Plone 6.x on Python 3.9 and newer.
+
 plone.rest 4.x.x supports Plone 5.2 and 6.x on Python 3.8 and newer.
 
 plone.rest 3.x.x supports Plone 5.2 on Python 2.7 and 3.6 to 3.8 and Plone 6.0 on Python 3.8 to 3.11.
diff --git a/news/178.internal b/news/178.internal
index 634cb72..f175d57 100644
--- a/news/178.internal
+++ b/news/178.internal
@@ -1 +1 @@
-Update Plone to 6.0.9 and 5.2.14 in buildout. Also removes buildout of unsupported Plone versions. @wesleybl
+Update Plone to 6.0.14 and 6.1.0b2 for testing. Also removes buildout of unsupported Plone versions. @wesleybl, @davisagli
diff --git a/news/4090.breaking b/news/4090.breaking
new file mode 100644
index 0000000..2c1f03a
--- /dev/null
+++ b/news/4090.breaking
@@ -0,0 +1 @@
+Drop support for Plone 5.2 and Python 3.8. @davisagli
diff --git a/news/4090.bugfix b/news/4090.bugfix
new file mode 100644
index 0000000..8528aef
--- /dev/null
+++ b/news/4090.bugfix
@@ -0,0 +1 @@
+Fix DeprecationWarnings. [maurits]
diff --git a/plone-5.2.x.cfg b/plone-5.2.x.cfg
deleted file mode 100644
index dbc7af7..0000000
--- a/plone-5.2.x.cfg
+++ /dev/null
@@ -1,4 +0,0 @@
-[buildout]
-extends =
-    https://dist.plone.org/release/5.2.14/versions.cfg
-    base.cfg
diff --git a/plone-6.0.x.cfg b/plone-6.0.x.cfg
index 3564243..e35457e 100644
--- a/plone-6.0.x.cfg
+++ b/plone-6.0.x.cfg
@@ -1,4 +1,4 @@
 [buildout]
 extends =
-    https://dist.plone.org/release/6.0.9/versions.cfg
+    https://dist.plone.org/release/6.0.14/versions.cfg
     base.cfg
diff --git a/plone-6.1.x.cfg b/plone-6.1.x.cfg
new file mode 100644
index 0000000..3728066
--- /dev/null
+++ b/plone-6.1.x.cfg
@@ -0,0 +1,4 @@
+[buildout]
+extends =
+    https://dist.plone.org/release/6.1.0b2/versions.cfg
+    base.cfg
diff --git a/pyproject.toml b/pyproject.toml
index 6e5db43..dd067c8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -116,7 +116,7 @@ Zope = [
   'Products.CMFCore', 'Products.CMFDynamicViewFTI',
 ]
 python-dateutil = ['dateutil']
-ignore-packages = ['plone.app.redirector']
+ignore-packages = ['plone.app.layout', 'plone.app.redirector', 'plone.base', 'Products.CMFPlone']
 
 ##
 # Add extra configuration options in .meta.toml:
diff --git a/requirements-5.2.txt b/requirements-5.2.txt
deleted file mode 100644
index 37660fa..0000000
--- a/requirements-5.2.txt
+++ /dev/null
@@ -1 +0,0 @@
--r https://dist.plone.org/release/5.2.14/requirements.txt
diff --git a/requirements-6.0.txt b/requirements-6.0.txt
index 12977a8..d75ea5c 100644
--- a/requirements-6.0.txt
+++ b/requirements-6.0.txt
@@ -1 +1 @@
--r https://dist.plone.org/release/6.0.9/requirements.txt
+-r https://dist.plone.org/release/6.0.14/requirements.txt
diff --git a/requirements-6.1.txt b/requirements-6.1.txt
new file mode 100644
index 0000000..1abfefe
--- /dev/null
+++ b/requirements-6.1.txt
@@ -0,0 +1 @@
+-r https://dist.plone.org/release/6.1.0b2/requirements.txt
diff --git a/requirements.txt b/requirements.txt
index 9471139..ea41d45 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1 @@
--r requirements-6.0.txt
+-r requirements-6.1.txt
diff --git a/setup.py b/setup.py
index 2471024..ce4735e 100644
--- a/setup.py
+++ b/setup.py
@@ -8,7 +8,7 @@ def read(*rnames):
     return open(os.path.join(os.path.dirname(__file__), *rnames)).read()
 
 
-version = "4.1.4.dev0"
+version = "5.0.0.dev0"
 
 long_description = read("README.rst") + "\n\n" + read("CHANGES.rst") + "\n\n"
 
@@ -24,11 +24,11 @@ def read(*rnames):
         "Development Status :: 5 - Production/Stable",
         "Environment :: Web Environment",
         "Framework :: Plone",
-        "Framework :: Plone :: 5.2",
         "Framework :: Plone :: 6.0",
+        "Framework :: Plone :: 6.1",
         "Framework :: Plone :: Core",
         "Framework :: Zope2",
-        "Framework :: Zope :: 4",
+        "Framework :: Zope :: 5",
         "License :: OSI Approved :: GNU General Public License (GPL)",
         "Operating System :: OS Independent",
         "Programming Language :: Python",
@@ -37,6 +37,7 @@ def read(*rnames):
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
+        "Programming Language :: Python :: 3.13",
         "Programming Language :: Python :: 3 :: Only",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],
@@ -57,14 +58,12 @@ def read(*rnames):
             "requests",
             "BTrees",
             "plone.app.contenttypes[test]",
-            "plone.app.layout",
             "plone.app.redirector",
             "plone.app.textfield",
             "plone.namedfile",
             "plone.testing",
             "z3c.relationfield",
             "zope.intid",
-            "plone.base",
         ]
     ),
     install_requires=[
diff --git a/src/plone/rest/patches.py b/src/plone/rest/patches.py
index 8f4cb5d..e61bbdd 100644
--- a/src/plone/rest/patches.py
+++ b/src/plone/rest/patches.py
@@ -12,30 +12,3 @@ def __before_publishing_traverse__(self, arg1, arg2=None):
         return
 
     return self._old___before_publishing_traverse__(arg1, arg2)
-
-
-PERMANENT_REDIRECT = {308: "Permanent Redirect"}
-
-
-def patch_zpublisher_status_codes(scope, unused_original, unused_replacement):
-    """Add '308 Permanent Redirect' to the list of status codes the ZPublisher
-    knows about. Otherwise setStatus() will turn it into a 500.
-
-    This is needed for up to and including Plone 5.1.
-    """
-    status_reasons = getattr(scope, "status_reasons", {})
-    if 308 in status_reasons:
-        # Already present in zExceptions >= 3.2 / Zope >= 4.0a1 / Plone 5.2
-        return
-
-    # Patch the forward mapping (code -> reason)
-    status_reasons.update(PERMANENT_REDIRECT)
-
-    # Update the reverse mapping
-    status_codes = getattr(scope, "status_codes", {})
-    key, val = PERMANENT_REDIRECT.items()[0]
-
-    status_codes["".join(val.split(" ")).lower()] = key
-    status_codes[val.lower()] = key
-    status_codes[key] = key
-    status_codes[str(key)] = key
diff --git a/src/plone/rest/patches.zcml b/src/plone/rest/patches.zcml
index a26791d..2b90ff8 100644
--- a/src/plone/rest/patches.zcml
+++ b/src/plone/rest/patches.zcml
@@ -14,14 +14,4 @@
       preserveOriginal="true"
       />
 
-  <monkey:patch
-      original="status_codes"
-      replacement=".patches.PERMANENT_REDIRECT"
-      module="ZPublisher.HTTPResponse"
-      handler=".patches.patch_zpublisher_status_codes"
-      description="Teach ZPublisher about status 308"
-      ignoreOriginal="True"
-      preconditions="Zope2-=4.0a1"
-      />
-
 </configure>
diff --git a/src/plone/rest/testing.py b/src/plone/rest/testing.py
index bcd4eeb..95e4d12 100644
--- a/src/plone/rest/testing.py
+++ b/src/plone/rest/testing.py
@@ -3,7 +3,7 @@
 from plone.app.testing import IntegrationTesting
 from plone.app.testing import PloneSandboxLayer
 from plone.rest.service import Service
-from plone.testing import z2
+from plone.testing import zope
 from zope.configuration import xmlconfig
 
 
@@ -22,7 +22,8 @@ def setUpZope(self, app, configurationContext):
     bases=(PLONE_REST_FIXTURE,), name="PloneRestLayer:Integration"
 )
 PLONE_REST_FUNCTIONAL_TESTING = FunctionalTesting(
-    bases=(PLONE_REST_FIXTURE, z2.ZSERVER_FIXTURE), name="PloneRestLayer:Functional"
+    bases=(PLONE_REST_FIXTURE, zope.WSGI_SERVER_FIXTURE),
+    name="PloneRestLayer:Functional",
 )
 
 
diff --git a/src/plone/rest/testing.zcml b/src/plone/rest/testing.zcml
index 2033039..c3f0295 100644
--- a/src/plone/rest/testing.zcml
+++ b/src/plone/rest/testing.zcml
@@ -54,42 +54,42 @@
   <plone:service
       method="GET"
       factory=".demo.Get"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="zope2.View"
       />
 
   <plone:service
       method="POST"
       factory=".demo.Post"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="cmf.AddPortalContent"
       />
 
   <plone:service
       method="PUT"
       factory=".demo.Put"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="cmf.ModifyPortalContent"
       />
 
   <plone:service
       method="DELETE"
       factory=".demo.Delete"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="zope2.DeleteObjects"
       />
 
   <plone:service
       method="PATCH"
       factory=".demo.Patch"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="cmf.ModifyPortalContent"
       />
 
   <plone:service
       method="OPTIONS"
       factory=".demo.Options"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="zope2.View"
       />
 
diff --git a/src/plone/rest/tests/test_traversal.py b/src/plone/rest/tests/test_traversal.py
index 43ee632..a7be671 100644
--- a/src/plone/rest/tests/test_traversal.py
+++ b/src/plone/rest/tests/test_traversal.py
@@ -1,9 +1,9 @@
 from base64 import b64encode
-from plone.app.layout.navigation.interfaces import INavigationRoot
 from plone.app.testing import setRoles
 from plone.app.testing import SITE_OWNER_NAME
 from plone.app.testing import SITE_OWNER_PASSWORD
 from plone.app.testing import TEST_USER_ID
+from plone.base.interfaces import INavigationRoot
 from plone.rest.service import Service
 from plone.rest.testing import PLONE_REST_INTEGRATION_TESTING
 from Products.SiteAccess.VirtualHostMonster import VirtualHostMonster
diff --git a/tox.ini b/tox.ini
index c30d780..081d87a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -100,7 +100,7 @@ set_env =
 ##
 deps =
     zope.testrunner
-    -c https://dist.plone.org/release/6.0-dev/constraints.txt
+    -c https://dist.plone.org/release/6.1-dev/constraints.txt
     
 ##
 # Specify additional deps in .meta.toml:
@@ -143,7 +143,7 @@ set_env =
 deps =
     coverage
     zope.testrunner
-    -c https://dist.plone.org/release/6.0-dev/constraints.txt
+    -c https://dist.plone.org/release/6.1-dev/constraints.txt
     
 commands =
     coverage run --branch --source plone.rest {envbindir}/zope-testrunner --quiet --all --test-path={toxinidir}/src -s plone.rest {posargs}
@@ -160,7 +160,7 @@ deps =
     twine
     build
     towncrier
-    -c https://dist.plone.org/release/6.0-dev/constraints.txt
+    -c https://dist.plone.org/release/6.1-dev/constraints.txt
     
 commands =
     # fake version to not have to install the package
@@ -188,7 +188,7 @@ allowlist_externals =
 deps =
     pipdeptree
     pipforester
-    -c https://dist.plone.org/release/6.0-dev/constraints.txt
+    -c https://dist.plone.org/release/6.1-dev/constraints.txt
     
 commands =
     # Generate the full dependency tree