diff --git a/apps/dav/lib/CalDAV/TipBroker.php b/apps/dav/lib/CalDAV/TipBroker.php
index a0b3c904493d3..43eff124f0bb1 100644
--- a/apps/dav/lib/CalDAV/TipBroker.php
+++ b/apps/dav/lib/CalDAV/TipBroker.php
@@ -126,7 +126,7 @@ protected function parseEventForOrganizer(VCalendar $calendar, array $eventInfo,
 
 				$message->significantChange =
 					$attendee['forceSend'] === 'REQUEST' ||
-					count($oldAttendeeInstances) != count($newAttendeeInstances) ||
+					count($oldAttendeeInstances) !== count($newAttendeeInstances) ||
 					count(array_diff($oldAttendeeInstances, $newAttendeeInstances)) > 0 ||
 					$oldEventInfo['significantChangeHash'] !== $eventInfo['significantChangeHash'];
 
diff --git a/apps/dav/tests/unit/CalDAV/TipBrokerTest.php b/apps/dav/tests/unit/CalDAV/TipBrokerTest.php
new file mode 100644
index 0000000000000..ae855628d9b1b
--- /dev/null
+++ b/apps/dav/tests/unit/CalDAV/TipBrokerTest.php
@@ -0,0 +1,185 @@
+<?php
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\DAV\Tests\unit\CalDAV;
+
+use OCA\DAV\CalDAV\TipBroker;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\ITip\ITipException;
+use Sabre\VObject\ITip\SameOrganizerForAllComponentsException;
+use Test\TestCase;
+
+class TipBrokerTest extends TestCase {
+
+	private TipBroker $broker;
+	private VCalendar $vCalendar1a;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->broker = new TipBroker();
+		// construct calendar with a 1 hour event and same start/end time zones
+		$this->vCalendar1a = new VCalendar();
+		/** @var VEvent $vEvent */
+		$vEvent = $this->vCalendar1a->add('VEVENT', []);
+		$vEvent->add('UID', '96a0e6b1-d886-4a55-a60d-152b31401dcc');
+        $vEvent->add('DTSTAMP', '20240701T000000Z');
+        $vEvent->add('CREATED', '20240701T000000Z');
+        $vEvent->add('LAST-MODIFIED', '20240701T000000Z');
+        $vEvent->add('SEQUENCE', '1');
+        $vEvent->add('STATUS', 'CONFIRMED');
+		$vEvent->add('DTSTART', '20240701T080000', ['TZID' => 'America/Toronto']);
+		$vEvent->add('DTEND', '20240701T090000', ['TZID' => 'America/Toronto']);
+		$vEvent->add('SUMMARY', 'Test Event');
+		$vEvent->add('ORGANIZER', 'mailto:organizer@testing.com', ['CN' => 'Organizer']);
+		$vEvent->add('ATTENDEE', 'mailto:attendee1@testing.com', [
+			'CN' => 'Attendee One',
+			'CUTYPE' => 'INDIVIDUAL',
+			'PARTSTAT' => 'NEEDS-ACTION',
+			'ROLE' => 'REQ-PARTICIPANT',
+			'RSVP' => 'TRUE'
+		]);
+	}
+
+	public function testParseEventForOrganizerOnCreate(): void {
+		
+        // construct calendar and generate event info for newly created event with one attendee
+        $calendar = clone $this->vCalendar1a;
+		$previousEventInfo = [
+			'organizer' => null,
+			'significantChangeHash' => '',
+			'attendees' => [],
+		];
+		$currentEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+		// test iTip generation
+		$messages = $this->callMethod($this->broker, 'parseEventForOrganizer', [$calendar, $currentEventInfo, $previousEventInfo]);
+        $this->assertCount(1, $messages);
+        $this->assertEquals('REQUEST', $messages[0]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[0]->sender);
+        $this->assertEquals($calendar->VEVENT->ATTENDEE[0]->getValue(), $messages[0]->recipient);
+
+	}
+
+    public function testParseEventForOrganizerOnModify(): void {
+		
+        // construct calendar and generate event info for modified event with one attendee
+        $calendar = clone $this->vCalendar1a;
+		$previousEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+        $calendar->VEVENT->{'LAST-MODIFIED'}->setValue('20240701T020000Z');
+        $calendar->VEVENT->SEQUENCE->setValue(2);
+        $calendar->VEVENT->SUMMARY->setValue('Test Event Modified');
+		$currentEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+		// test iTip generation
+		$messages = $this->callMethod($this->broker, 'parseEventForOrganizer', [$calendar, $currentEventInfo, $previousEventInfo]);
+        $this->assertCount(1, $messages);
+        $this->assertEquals('REQUEST', $messages[0]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[0]->sender);
+        $this->assertEquals($calendar->VEVENT->ATTENDEE[0]->getValue(), $messages[0]->recipient);
+
+	}
+
+    public function testParseEventForOrganizerOnDelete(): void {
+		
+        // construct calendar and generate event info for modified event with one attendee
+        $calendar = clone $this->vCalendar1a;
+		$previousEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+		$currentEventInfo = $previousEventInfo;
+        $currentEventInfo['attendees'] = [];
+        ++$currentEventInfo['sequence'];
+		// test iTip generation
+		$messages = $this->callMethod($this->broker, 'parseEventForOrganizer', [$calendar, $currentEventInfo, $previousEventInfo]);
+        $this->assertCount(1, $messages);
+        $this->assertEquals('CANCEL', $messages[0]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[0]->sender);
+        $this->assertEquals($calendar->VEVENT->ATTENDEE[0]->getValue(), $messages[0]->recipient);
+
+	}
+
+    public function testParseEventForOrganizerOnStatusCancelled(): void {
+		
+        // construct calendar and generate event info for modified event with one attendee
+        $calendar = clone $this->vCalendar1a;
+		$previousEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+        $calendar->VEVENT->{'LAST-MODIFIED'}->setValue('20240701T020000Z');
+        $calendar->VEVENT->SEQUENCE->setValue(2);
+        $calendar->VEVENT->STATUS->setValue('CANCELLED');
+		$currentEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+		// test iTip generation
+		$messages = $this->callMethod($this->broker, 'parseEventForOrganizer', [$calendar, $currentEventInfo, $previousEventInfo]);
+        $this->assertCount(1, $messages);
+        $this->assertEquals('CANCEL', $messages[0]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[0]->sender);
+        $this->assertEquals($calendar->VEVENT->ATTENDEE[0]->getValue(), $messages[0]->recipient);
+
+	}
+
+    public function testParseEventForOrganizerOnAddAttendee(): void {
+		
+        // construct calendar and generate event info for modified event with two attendees
+        $calendar = clone $this->vCalendar1a;
+		$previousEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+        $calendar->VEVENT->{'LAST-MODIFIED'}->setValue('20240701T020000Z');
+        $calendar->VEVENT->SEQUENCE->setValue(2);
+        $calendar->VEVENT->add('ATTENDEE', 'mailto:attendee2@testing.com', [
+			'CN' => 'Attendee Two',
+			'CUTYPE' => 'INDIVIDUAL',
+			'PARTSTAT' => 'NEEDS-ACTION',
+			'ROLE' => 'REQ-PARTICIPANT',
+			'RSVP' => 'TRUE'
+		]);
+		$currentEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+		// test iTip generation
+		$messages = $this->callMethod($this->broker, 'parseEventForOrganizer', [$calendar, $currentEventInfo, $previousEventInfo]);
+        $this->assertCount(2, $messages);
+        $this->assertEquals('REQUEST', $messages[0]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[0]->sender);
+        $this->assertEquals($calendar->VEVENT->ATTENDEE[0]->getValue(), $messages[0]->recipient);
+        $this->assertEquals('REQUEST', $messages[1]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[1]->sender);
+        $this->assertEquals($calendar->VEVENT->ATTENDEE[1]->getValue(), $messages[1]->recipient);
+
+	}
+
+    public function testParseEventForOrganizerOnRemoveAttendee(): void {
+		
+        // construct calendar and generate event info for modified event with two attendees
+        $calendar = clone $this->vCalendar1a;
+        $calendar->VEVENT->add('ATTENDEE', 'mailto:attendee2@testing.com', [
+			'CN' => 'Attendee Two',
+			'CUTYPE' => 'INDIVIDUAL',
+			'PARTSTAT' => 'NEEDS-ACTION',
+			'ROLE' => 'REQ-PARTICIPANT',
+			'RSVP' => 'TRUE'
+		]);
+		$previousEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+        $calendar->VEVENT->{'LAST-MODIFIED'}->setValue('20240701T020000Z');
+        $calendar->VEVENT->SEQUENCE->setValue(2);
+        $calendar->VEVENT->remove('ATTENDEE');
+        $calendar->VEVENT->add('ATTENDEE', 'mailto:attendee1@testing.com', [
+			'CN' => 'Attendee One',
+			'CUTYPE' => 'INDIVIDUAL',
+			'PARTSTAT' => 'NEEDS-ACTION',
+			'ROLE' => 'REQ-PARTICIPANT',
+			'RSVP' => 'TRUE'
+		]);
+		$currentEventInfo = $this->callMethod($this->broker, 'parseEventInfo', [$calendar]);
+		// test iTip generation
+		$messages = $this->callMethod($this->broker, 'parseEventForOrganizer', [$calendar, $currentEventInfo, $previousEventInfo]);
+        $this->assertCount(2, $messages);
+        $this->assertEquals('REQUEST', $messages[0]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[0]->sender);
+        $this->assertEquals($calendar->VEVENT->ATTENDEE[0]->getValue(), $messages[0]->recipient);
+        $this->assertEquals('CANCEL', $messages[1]->method);
+        $this->assertEquals($calendar->VEVENT->ORGANIZER->getValue(), $messages[1]->sender);
+        $this->assertEquals('mailto:attendee2@testing.com', $messages[1]->recipient);
+
+	}
+
+	public static function callMethod($obj, $name, array $args) {
+        $class = new \ReflectionClass($obj);
+        $method = $class->getMethod($name);
+        return $method->invokeArgs($obj, $args);
+    }
+}