diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 02df32d7..1f86951d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -15,7 +15,8 @@ jobs:
           - '5.0'
           - '5.1'
           - '5.2'
-        python-version: ['2.7', '3.6', '3.7', '3.8']
+          - '6.0'
+        python-version: ['2.7', '3.6', '3.7', '3.8', '3.9']
         layer:
           - Portlet_AjaxDisabled
           - Portlet_AjaxEnabled
@@ -34,12 +35,24 @@ jobs:
             python-version: 3.7
           - plone-version: 5.0
             python-version: 3.8
+          - plone-version: 5.0
+            python-version: 3.9
           - plone-version: 5.1
             python-version: 3.6
           - plone-version: 5.1
             python-version: 3.7
           - plone-version: 5.1
             python-version: 3.8
+          - plone-version: 5.1
+            python-version: 3.9
+          # 5.2 does not run on 3.9
+          - plone-version: 5.2
+            python-version: 3.9
+          # 6.0 does not run on 2.7/3.6
+          - plone-version: 6.0
+            python-version: 2.7
+          - plone-version: 6.0
+            python-version: 3.6
           # Save some time by not running all the robot tests
           - python-version: 3.6
             layer: Portlet_AjaxDisabled
@@ -56,7 +69,9 @@ jobs:
             coverage: coverage
           - plone-version: 5.2
             coverage: no_coverage
-          
+          - plone-version: 6.0
+            coverage: coverage
+
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python
@@ -94,10 +109,17 @@ jobs:
             echo "[buildout]" > $HOME/.buildout/default.cfg
             echo "download-cache = $HOME/buildout-cache/downloads" >> $HOME/.buildout/default.cfg
             echo "eggs-directory = $HOME/buildout-cache/eggs" >> $HOME/.buildout/default.cfg
-      - name: bootstrap buildout
+      - name: bootstrap buildout (old-school)
+        if: ${{ matrix.python-version == '2.7' }}
         run: |
           ./bootstrap.sh test-${{ matrix.plone-version }}.x.cfg
           ls -al
+      - name: bootstrap buildout (new-way)
+        if: ${{ matrix.python-version != '2.7' }}
+        run: |
+          python -m venv .
+          bin/pip install -r requirements-${{ matrix.plone-version }}.x.txt
+          ls -al
       - name: buildout
         run: |
           bin/buildout -t 10 -Nc test-${{ matrix.plone-version }}.x.cfg
@@ -110,12 +132,12 @@ jobs:
             chromedriver --url-base=/wd/hub &
             sudo Xvfb -ac :99 -screen 0 1280x1024x24 > /dev/null 2>&1 & # optional
             sleep 3
-            bin/test --all  --layer ${{ matrix.layer }} --list-tests            
+            bin/test --all  --layer ${{ matrix.layer }} --list-tests
             bin/test --all  --layer ${{ matrix.layer }}
       - name: test unit
         if: ${{ matrix.coverage != 'coverage' && matrix.layer == 'unit' }}
         run: |
-            bin/test --unit --list-tests            
+            bin/test --unit --list-tests
             bin/test --unit
       - name: createcoverage
         if: ${{ matrix.coverage == 'coverage' && matrix.layer != 'unit' }}
@@ -124,13 +146,13 @@ jobs:
             chromedriver --url-base=/wd/hub &
             sudo Xvfb -ac :99 -screen 0 1280x1024x24 > /dev/null 2>&1 & # optional
             sleep 3
-            bin/test --all  --layer ${{ matrix.layer }} --list-tests            
+            bin/test --all  --layer ${{ matrix.layer }} --list-tests
             bin/createcoverage -t '--all --layer ${{ matrix.layer }}'
             bin/coverage json -i
       - name: createcoverage
         if: ${{ matrix.coverage == 'coverage' && matrix.layer == 'unit' }}
         run: |
-            bin/test --unit --list-tests            
+            bin/test --unit --list-tests
             bin/createcoverage -t '--unit'
             bin/coverage json -i
       - name: Coveralls
@@ -141,11 +163,11 @@ jobs:
           flag-name: ${{ matrix.plone-version }}-${{ matrix.python-version }}-${{ matrix.layer }}
       - name: code-analysis
         if: always()
-        run: echo "${{ matrix.plone-version }}" | grep 5.1 || bin/code-analysis
+        run: echo "${{ matrix.plone-version }}" | grep 5.2 || bin/code-analysis
       - name: black
-        if: ${{ matrix.python-version == '3.8' }}
+        if: ${{ matrix.python-version == '3.9' }}
         run: |
-          pip install black
+          pip install "black==21.12b0"
           black --check src
       - name: Artifact Robot Test Report
         if: failure()
diff --git a/CHANGES.rst b/CHANGES.rst
index 1494dedc..6168ce0b 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -6,12 +6,15 @@ Changelog
 
 Breaking Change:
 
-- Add idx parameter to display_modifier call, so that we can use the index name to resolve the correct translated taxonomy titles in collective.taxonomy. 
+- Add idx parameter to display_modifier call, so that we can use the index name to resolve the correct translated taxonomy titles in collective.taxonomy.
   This means that the display_modifier method in the groupby_modifier adapters needs to expect this parameter too!
   [MrTango]
 
 Features:
 
+- Support and Test Plone 6.
+  [jensens]
+
 - Add a module global COLLECTIONISH_TARGETS to c.c.tiles to register other tiles with collections than plone.app.standardtiles.contentlisting.
   [jensens]
 
diff --git a/requirements-5.2.x.txt b/requirements-5.2.x.txt
new file mode 100644
index 00000000..6fbe573d
--- /dev/null
+++ b/requirements-5.2.x.txt
@@ -0,0 +1 @@
+-r https://dist.plone.org/release/5.2-latest/requirements.txt
\ No newline at end of file
diff --git a/requirements-6.0.x.txt b/requirements-6.0.x.txt
new file mode 100644
index 00000000..882d130f
--- /dev/null
+++ b/requirements-6.0.x.txt
@@ -0,0 +1 @@
+-r https://dist.plone.org/release/6.0-latest/requirements.txt
\ No newline at end of file
diff --git a/setup.py b/setup.py
index 0bf3687c..f1d258a1 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@
 import os
 
 
-version = "3.6.dev0"
+version = "4.0.dev0"
 
 
 def read(*rnames):
@@ -26,11 +26,14 @@ def read(*rnames):
         "Framework :: Plone :: 5.0",
         "Framework :: Plone :: 5.1",
         "Framework :: Plone :: 5.2",
+        "Framework :: Plone :: 6.0",
         "Framework :: Plone :: Addon",
         "Programming Language :: Python",
         "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],
     keywords="plone collection filter faceted tagcloud tags",
diff --git a/test-5.0.x.cfg b/test-5.0.x.cfg
index 6d5ea05d..85cf5dbc 100644
--- a/test-5.0.x.cfg
+++ b/test-5.0.x.cfg
@@ -28,3 +28,5 @@ plone.tiles = 2.0.0
 plone.jsonserializer = 0.9.6
 
 plone.formwidget.geolocation = < 2.2.2 # Introduced a dep on CMFPlone 5.2
+
+six = 1.16.0
\ No newline at end of file
diff --git a/test-5.1.x.cfg b/test-5.1.x.cfg
index 197a209d..fd6394f4 100644
--- a/test-5.1.x.cfg
+++ b/test-5.1.x.cfg
@@ -21,3 +21,4 @@ configparser = 3.8.1
 
 plone.formwidget.geolocation = < 2.2.2 # Introduced a dep on CMFPlone 5.2
 
+six = 1.16.0
\ No newline at end of file
diff --git a/test-6.0.x.cfg b/test-6.0.x.cfg
new file mode 100644
index 00000000..f75cd598
--- /dev/null
+++ b/test-6.0.x.cfg
@@ -0,0 +1,19 @@
+[buildout]
+extends =
+    https://raw.githubusercontent.com/collective/buildout.plonetest/master/test-6.0.x.cfg
+    https://raw.githubusercontent.com/collective/buildout.plonetest/master/qa.cfg
+    base.cfg
+
+parts +=
+    test
+    createcoverage
+
+parts -=
+    code-analysis
+
+package-name = collective.collectionfilter
+package-extras = [test]
+test-eggs =
+
+[versions:python3]
+coverage = >=3.7