diff --git a/modoboa/calendars/backends/caldav_.py b/modoboa/calendars/backends/caldav_.py
index 7bc513ebe..03a53849b 100644
--- a/modoboa/calendars/backends/caldav_.py
+++ b/modoboa/calendars/backends/caldav_.py
@@ -23,7 +23,9 @@ class Caldav_Backend(CalendarBackend):
         """Constructor."""
         super().__init__(calendar)
         server_url = smart_str(param_tools.get_global_parameter("server_location"))
-        self.client = caldav.DAVClient(server_url, username=username, password=password)
+        self.client = caldav.DAVClient(
+            server_url, username=username, password=str(password)
+        )
         if self.calendar:
             self.remote_cal = Calendar(self.client, calendar.encoded_path)
 
diff --git a/pyproject.toml b/pyproject.toml
index 31ebf63d2..f1ca582ff 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -77,7 +77,7 @@ dependencies = [
         # User
         "drf-nested-routers",
         "vobject",
-        "caldav==2.0.1",
+        "caldav==2.1.2",
         # Amavis
         "html2text",
         "idna",