diff --git a/src/tests/Infrastructure/DavTest.php b/src/tests/Infrastructure/DavTest.php
--- a/src/tests/Infrastructure/DavTest.php
+++ b/src/tests/Infrastructure/DavTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Infrastructure;
 
+use App\Backends\DAV;
 use Tests\TestCase;
 
 /**
@@ -201,6 +202,64 @@
         $this->assertStringContainsString("<d:href>$href</d:href>", $data);
     }
 
+    /**
+     * Test calendar event creation
+     */
+    public function testCalendarEventsCreation(): void
+    {
+        $email = $this->user->email;
+        $vevent = <<<EOF
+            BEGIN:VCALENDAR
+            METHOD:PUBLISH
+            PRODID:Microsoft Exchange Server 2010
+            VERSION:2.0
+            BEGIN:VTIMEZONE
+            TZID:Central European Standard Time
+            BEGIN:STANDARD
+            DTSTART:16010101T030000
+            TZOFFSETFROM:+0200
+            TZOFFSETTO:+0100
+            RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10
+            END:STANDARD
+            BEGIN:DAYLIGHT
+            DTSTART:16010101T020000
+            TZOFFSETFROM:+0100
+            TZOFFSETTO:+0200
+            RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3
+            END:DAYLIGHT
+            END:VTIMEZONE
+            BEGIN:VEVENT
+            ORGANIZER;CN=Aleksander Machniak:mailto:{$email}
+            ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN=Aleksander
+             Machniak:mailto:test@kolab.org
+            ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN=Alec Machn
+             iak:mailto:alec@outlook.com
+            DESCRIPTION:*test to ms*
+            UID:1F3C13D7E99642A75ABE23D50487B454-8FE68B2E68E1B348
+            SUMMARY:test to ms
+            DTSTART;TZID=Central European Standard Time:20231121T120000
+            DTEND;TZID=Central European Standard Time:20231121T123000
+            CLASS:PUBLIC
+            PRIORITY:5
+            DTSTAMP:20231120T145005Z
+            TRANSP:OPAQUE
+            STATUS:CONFIRMED
+            SEQUENCE:0
+            END:VEVENT
+            END:VCALENDAR
+            EOF;
+
+        $event = new DAV\Opaque(str_replace("\n", "\r\n", $vevent));
+        $event->contentType = 'text/calendar; charset=utf-8';
+        $event->href = "calendars/user/{$email}/Default/1F3C13D7E99642A75ABE23D50487B454-8FE68B2E68E1B348.ics";
+
+        $dav = new DAV($this->user->email, 'simple123');
+
+        // The error that does not make sense (on Cyrus DAV) is 403 with this in the XML body:
+        // Failed iTIP restrictions for ATTENDEE property. Expected 0 instances of the property and got 2.
+        $this->assertTrue($dav->create($event) !== false);
+    }
+
     /**
      * Thunderbird does this and relies on the WWW-Authenticate header response to
      * start sending authenticated requests.