diff --git a/apps/dav/lib/CalDAV/Schedule/IMipPlugin.php b/apps/dav/lib/CalDAV/Schedule/IMipPlugin.php
index 0000000..patched33 100644
--- a/apps/dav/lib/CalDAV/Schedule/IMipPlugin.php
+++ b/apps/dav/lib/CalDAV/Schedule/IMipPlugin.php
@@ -482,6 +482,49 @@ class IMipPlugin extends ServerPlugin {

         $event = $this->eventLookup->getByUid($uid);

+        if (!$event) {
+            \OC::$server->getLogger()->debug(
+                'iMip: UID not found, running fallback match',
+                ['app' => 'dav', 'uid' => $uid]
+            );
+
+            try {
+                $vcalendar = \Sabre\VObject\Reader::read($message);
+
+                if (isset($vcalendar->VEVENT)) {
+                    $vevent = $vcalendar->VEVENT;
+
+                    $organizer = isset($vevent->ORGANIZER) ? (string)$vevent->ORGANIZER : '';
+                    $dtstart = isset($vevent->DTSTART) ? $vevent->DTSTART->getDateTime() : null;
+
+                    if ($dtstart && $organizer) {
+                        $from = (clone $dtstart)->modify('-1 hour');
+                        $to   = (clone $dtstart)->modify('+1 hour');
+
+                        $events = $this->eventLookup->getEvents('', $from, $to);
+
+                        foreach ($events as $candidate) {
+                            $cOrg = $candidate->getOrganizer();
+
+                            if ($cOrg && stripos($cOrg, $organizer) !== false) {
+                                \OC::$server->getLogger()->debug(
+                                    'iMip fallback matched event',
+                                    ['app' => 'dav']
+                                );
+
+                                $event = $candidate;
+                                break;
+                            }
+                        }
+                    }
+                }
+            } catch (\Throwable $e) {
+                \OC::$server->getLogger()->debug(
+                    'iMip fallback error',
+                    ['app' => 'dav', 'error' => $e->getMessage()]
+                );
+            }
+        }
+
         if (!$event) {
             $this->logger->debug('Could not find event for iMip response', ['app' => 'dav']);
             return;