diff --git a/setup.py b/setup.py
index a42bdc1..4e2a2d8 100644
--- a/setup.py
+++ b/setup.py
@@ -49,13 +49,13 @@ def read(*pathnames):
     python_requires=">=3.8",
     install_requires=[
         "setuptools",
+        "plone.base",
         "plone.supermodel",
         "plone.api >= 1.5",
         "plone.app.registry",
         "plone.app.dexterity",
         "plone.synchronize",
         "lxml",
-        "six >= 1.12",
     ],
     extras_require={
         "dev": [
diff --git a/src/collective/taxonomy/behavior.py b/src/collective/taxonomy/behavior.py
index 2322214..85aabd0 100644
--- a/src/collective/taxonomy/behavior.py
+++ b/src/collective/taxonomy/behavior.py
@@ -6,6 +6,7 @@
 from plone.autoform.interfaces import IFormFieldProvider
 from plone.autoform.interfaces import WIDGETS_KEY
 from plone.autoform.interfaces import WRITE_PERMISSIONS_KEY
+from plone.base.utils import safe_text
 from plone.behavior.interfaces import IBehavior
 from plone.dexterity.interfaces import IDexterityContent
 from plone.indexer.interfaces import IIndexer
@@ -17,7 +18,6 @@
 from plone.supermodel.model import Schema
 from plone.supermodel.model import SchemaClass
 from Products.CMFCore.utils import getToolByName
-from Products.CMFPlone.utils import safe_unicode
 from Products.PluginIndexes.KeywordIndex.KeywordIndex import KeywordIndex
 from Products.ZCatalog.Catalog import CatalogError
 from Products.ZCatalog.interfaces import IZCatalog
@@ -118,9 +118,9 @@ def activateSearchable(self):
         def add(name, value):
             registry.records[prefix + "." + name] = value
 
-        add("title", Record(field.TextLine(), safe_unicode(self.field_title)))
+        add("title", Record(field.TextLine(), safe_text(self.field_title)))
         add("enabled", Record(field.Bool(), True))
-        add("group", Record(field.TextLine(), safe_unicode("Taxonomy")))
+        add("group", Record(field.TextLine(), safe_text("Taxonomy")))
         add(
             "operations",
             Record(
@@ -129,11 +129,11 @@ def add(name, value):
             ),
         )
         add(
-            "vocabulary", Record(field.TextLine(), safe_unicode(self.vocabulary_name))
+            "vocabulary", Record(field.TextLine(), safe_text(self.vocabulary_name))
         )  # noqa: E501
         add("fetch_vocabulary", Record(field.Bool(), True))
         add("sortable", Record(field.Bool(), False))
-        add("description", Record(field.Text(), safe_unicode("")))
+        add("description", Record(field.Text(), safe_text("")))
 
     def addIndex(self):
         context = getSite()
@@ -194,15 +194,15 @@ def generateInterface(self):
 
         if hasattr(self, "is_single_select") and self.is_single_select:
             select_field = schema.Choice(
-                title=_(safe_unicode(self.field_title)),
-                description=_(safe_unicode(self.field_description)),
+                title=_(safe_text(self.field_title)),
+                description=_(safe_text(self.field_description)),
                 required=self.is_required,
                 vocabulary=self.vocabulary_name,
             )
         else:
             select_field = schema.List(
-                title=_(safe_unicode(self.field_title)),
-                description=_(safe_unicode(self.field_description)),
+                title=_(safe_text(self.field_title)),
+                description=_(safe_text(self.field_description)),
                 required=self.is_required,
                 min_length=self.is_required and 1 or 0,
                 value_type=schema.Choice(
diff --git a/src/collective/taxonomy/browser.py b/src/collective/taxonomy/browser.py
index 5b50097..89cfa0a 100644
--- a/src/collective/taxonomy/browser.py
+++ b/src/collective/taxonomy/browser.py
@@ -2,8 +2,8 @@
 from plone import api
 from plone.app.contenttypes.browser.collection import CollectionView
 from plone.app.vocabularies.metadatafields import get_field_label
+from plone.base.utils import safe_callable
 from plone.behavior.interfaces import IBehavior
-from Products.CMFPlone.utils import safe_callable
 from Products.Five.browser import BrowserView
 from zope.component import getSiteManager
 from zope.component import queryUtility
diff --git a/src/collective/taxonomy/controlpanel.py b/src/collective/taxonomy/controlpanel.py
index 87c5739..2aa4bc3 100644
--- a/src/collective/taxonomy/controlpanel.py
+++ b/src/collective/taxonomy/controlpanel.py
@@ -7,9 +7,9 @@
 from io import BytesIO
 from plone import api
 from plone.app.registry.browser import controlpanel
+from plone.base.interfaces import IPloneSiteRoot
 from plone.behavior.interfaces import IBehavior
 from plone.memoize import view
-from Products.CMFPlone.interfaces import IPloneSiteRoot
 from Products.Five.browser import BrowserView
 from z3c.form import button
 from z3c.form import field
diff --git a/src/collective/taxonomy/exportimport.py b/src/collective/taxonomy/exportimport.py
index 8f138c4..e0b98a3 100644
--- a/src/collective/taxonomy/exportimport.py
+++ b/src/collective/taxonomy/exportimport.py
@@ -5,10 +5,10 @@
 from io import BytesIO
 from io import StringIO
 from lxml.etree import fromstring
+from plone.base.utils import safe_text
 from plone.behavior.interfaces import IBehavior
 
 import configparser
-import six
 
 
 def parseConfigFile(data):
@@ -94,7 +94,7 @@ def exportTaxonomy(context):
             for name in ["title", "description", "default_language"]:
                 value = getattr(taxonomy, name, None)
                 if value:
-                    config.set("taxonomy", name, six.ensure_text(value))
+                    config.set("taxonomy", name, safe_text(value))
 
             for name in [
                 "field_title",
@@ -105,7 +105,7 @@ def exportTaxonomy(context):
             ]:
                 value = getattr(behavior, name, None)
                 if value is not None:
-                    config.set("taxonomy", name, six.ensure_text(value))
+                    config.set("taxonomy", name, safe_text(value))
 
             for name in ["is_single_select", "is_required"]:
                 value = getattr(behavior, name, None)
diff --git a/src/collective/taxonomy/indexer.py b/src/collective/taxonomy/indexer.py
index 1295df6..008cc01 100644
--- a/src/collective/taxonomy/indexer.py
+++ b/src/collective/taxonomy/indexer.py
@@ -3,15 +3,14 @@
 from collections.abc import Iterable
 from collective.taxonomy.interfaces import ITaxonomy
 from plone import api
+from plone.base.interfaces import IPloneSiteRoot
 from plone.dexterity.interfaces import IDexterityContent
 from plone.indexer.interfaces import IIndexer
-from Products.CMFPlone.interfaces import IPloneSiteRoot
 from Products.ZCatalog.interfaces import IZCatalog
 from zope.component import adapter
 from zope.interface import implementer
 
 import logging
-import six
 
 
 logger = logging.getLogger("collective.taxonomy")
diff --git a/src/collective/taxonomy/restapi/services/taxonomy/configure.zcml b/src/collective/taxonomy/restapi/services/taxonomy/configure.zcml
index 24d67bd..4d2f161 100644
--- a/src/collective/taxonomy/restapi/services/taxonomy/configure.zcml
+++ b/src/collective/taxonomy/restapi/services/taxonomy/configure.zcml
@@ -7,7 +7,7 @@
       method="GET"
       accept="application/json,application/schema+json"
       factory=".get.TaxonomyGet"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="zope2.View"
       name="@taxonomy"
       />
@@ -16,7 +16,7 @@
       method="GET"
       accept="application/json"
       factory=".schema.TaxonomyGetSchema"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="zope2.View"
       name="@taxonomySchema"
       />
@@ -24,7 +24,7 @@
   <plone:service
       method="POST"
       factory=".add.TaxonomyPost"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="cmf.ManagePortal"
       name="@taxonomy"
       />
@@ -32,7 +32,7 @@
   <plone:service
       method="DELETE"
       factory=".delete.TaxonomyDelete"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="cmf.ManagePortal"
       name="@taxonomy"
       />
@@ -40,7 +40,7 @@
   <plone:service
       method="PATCH"
       factory=".update.TaxonomyPatch"
-      for="Products.CMFPlone.interfaces.IPloneSiteRoot"
+      for="plone.base.interfaces.IPloneSiteRoot"
       permission="cmf.ManagePortal"
       name="@taxonomy"
       />
diff --git a/src/collective/taxonomy/tests/test_json.py b/src/collective/taxonomy/tests/test_json.py
index 4996148..0213f1f 100644
--- a/src/collective/taxonomy/tests/test_json.py
+++ b/src/collective/taxonomy/tests/test_json.py
@@ -5,7 +5,6 @@
 from plone.app.testing.interfaces import TEST_USER_NAME
 
 import json
-import six
 import unittest
 
 
@@ -103,7 +102,6 @@ def test_generate_json(self):
         )
 
 
-@unittest.skipIf(six.PY2, "Those tests run just for Python 3")
 class TestEditDataJson(unittest.TestCase):
     """Test Edit Data JSON view."""
 
diff --git a/src/collective/taxonomy/tests/test_setup.py b/src/collective/taxonomy/tests/test_setup.py
index 8adba46..4697e17 100644
--- a/src/collective/taxonomy/tests/test_setup.py
+++ b/src/collective/taxonomy/tests/test_setup.py
@@ -4,29 +4,12 @@
 from plone import api
 from plone.app.testing import setRoles
 from plone.app.testing import TEST_USER_ID
+from plone.base.utils import get_installer
 from Products.CMFCore.utils import getToolByName
 
 import unittest
 
 
-no_get_installer = False
-
-try:
-    from Products.CMFPlone.utils import get_installer
-except Exception:
-    # Quick shim for 5.1 api change
-
-    class get_installer:
-        def __init__(self, portal, request):
-            self.installer = getToolByName(portal, "portal_quickinstaller")
-
-        def is_product_installed(self, name):
-            return self.installer.isProductInstalled(name)
-
-        def uninstall_product(self, name):
-            return self.installer.uninstallProducts([name])
-
-
 class TestSetup(unittest.TestCase):
     """Test that collective.taxonomy is properly installed."""