diff --git a/.github/workflows/plugin.yml b/.github/workflows/plugin.yml
index 4fc4cd8..e97b7b7 100644
--- a/.github/workflows/plugin.yml
+++ b/.github/workflows/plugin.yml
@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     services:
       postgres:
-        image: postgres:11
+        image: postgres:12
         env:
           POSTGRES_USER: postgres
           POSTGRES_PASSWORD: postgres
@@ -41,20 +41,24 @@ jobs:
     strategy:
       matrix:
         database: ['postgres', 'mysql']
-        python-version: [3.7, 3.8, 3.9]
+        python-version: [3.8, 3.9, '3.10']
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
-          sudo apt-get update -y && sudo apt-get install -y librrd-dev rrdtool 
+          sudo apt-get update -y \
+          && sudo apt-get update -y && sudo apt-get install -y librrd-dev rrdtool
           python -m pip install --upgrade pip
-          pip install -e git+https://github.com/modoboa/modoboa.git#egg=modoboa
+          git clone https://github.com/modoboa/modoboa.git
+          cd modoboa
+          python setup.py develop
+          cd ..
           pip install -r requirements.txt
           pip install -r test-requirements.txt
           python setup.py develop
diff --git a/modoboa_radicale/backends/caldav_.py b/modoboa_radicale/backends/caldav_.py
index c79ea9a..2fbc5af 100644
--- a/modoboa_radicale/backends/caldav_.py
+++ b/modoboa_radicale/backends/caldav_.py
@@ -14,6 +14,7 @@
 from modoboa.parameters import tools as param_tools
 
 from . import CalendarBackend
+from .. import constants
 
 
 class Caldav_Backend(CalendarBackend):
@@ -24,9 +25,17 @@ def __init__(self, username, password, calendar=None):
         super(Caldav_Backend, self).__init__(calendar)
         server_url = smart_str(
             param_tools.get_global_parameter("server_location"))
+        ssl_verify_cert = param_tools.get_global_parameter("ssl_verify_cert")
+        if ssl_verify_cert == constants.VERIFY:
+            ssl_verify_cert = True
+        elif ssl_verify_cert == constants.NO_VERIFY:
+            ssl_verify_cert = False
+        elif ssl_verify_cert == constants.PATH:
+            ssl_verify_cert = param_tools.get_global_parameter("ssl_ca_bundle_path")
         self.client = caldav.DAVClient(
             server_url,
-            username=username, password=password)
+            username=username, password=password,
+            ssl_verify_cert=ssl_verify_cert)
         if self.calendar:
             self.remote_cal = Calendar(self.client, calendar.encoded_path)
 
diff --git a/modoboa_radicale/constants.py b/modoboa_radicale/constants.py
new file mode 100644
index 0000000..ca67365
--- /dev/null
+++ b/modoboa_radicale/constants.py
@@ -0,0 +1,5 @@
+"""Constants for modoboa-radicale"""
+
+VERIFY = 1
+NO_VERIFY = 2
+PATH = 3
diff --git a/modoboa_radicale/forms.py b/modoboa_radicale/forms.py
index ce11b2b..0add122 100644
--- a/modoboa_radicale/forms.py
+++ b/modoboa_radicale/forms.py
@@ -6,6 +6,14 @@
 from modoboa.lib import form_utils
 from modoboa.parameters import forms as param_forms
 
+from . import constants
+
+SSL_VERIFY_CHOICES = (
+    (constants.VERIFY, ugettext_lazy("Verify")),
+    (constants.NO_VERIFY, ugettext_lazy("Skip verification")),
+    (constants.PATH, ugettext_lazy("Provide CA bundle"))
+)
+
 
 class ParametersForm(param_forms.AdminParametersForm):
     """Global parameters."""
@@ -56,3 +64,23 @@ class ParametersForm(param_forms.AdminParametersForm):
             "Maximum size in bytes of imported ICS files "
             "(or KB, MB, GB if specified)")
     )
+
+    ssl_verify_cert = forms.ChoiceField(
+        choices=SSL_VERIFY_CHOICES,
+        initial=constants.VERIFY,
+        label=ugettext_lazy("Type of ssl verification"),
+        help_text=ugettext_lazy("It might be needed to set to custom "
+            "and set a CA bundle or set to 'Skip verification' "
+            "in case of a self-signed cert")
+        )
+
+    ssl_ca_bundle_path = forms.CharField(
+        label=ugettext_lazy("Path to CA bundle"),
+        initial="",
+        help_text=ugettext_lazy(
+            "Path to the CA bundle. ")
+        )
+
+    visibility_rules = {
+        "ssl_ca_bundle_path": f"ssl_verify_cert={constants.PATH}"
+        }
diff --git a/test_project/test_project/settings.py b/test_project/test_project/settings.py
index 7dc52a3..edb2f86 100644
--- a/test_project/test_project/settings.py
+++ b/test_project/test_project/settings.py
@@ -78,6 +78,9 @@
     'modoboa.dnstools',
     'modoboa.policyd',
     'modoboa.maillog',
+    'modoboa.dmarc',
+    'modoboa.pdfcredentials',
+    'modoboa.imap_migration',
     # Modoboa extensions here.
     'modoboa_radicale',
 )