diff --git a/lib/AppInfo/Application.php b/lib/AppInfo/Application.php
index 5db73bb3e..bbce42d64 100644
--- a/lib/AppInfo/Application.php
+++ b/lib/AppInfo/Application.php
@@ -16,6 +16,7 @@
 use OCA\Activity\Data;
 use OCA\Activity\FilesHooksStatic;
 use OCA\Activity\GroupHelper;
+use OCA\Activity\Listener\AddMissingIndicesListener;
 use OCA\Activity\Listener\LoadSidebarScripts;
 use OCA\Activity\Listener\SetUserDefaults;
 use OCA\Activity\Listener\ShareEventListener;
@@ -29,6 +30,7 @@
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
+use OCP\DB\Events\AddMissingIndicesEvent;
 use OCP\IConfig;
 use OCP\IDateTimeFormatter;
 use OCP\IDBConnection;
@@ -127,6 +129,7 @@ public function register(IRegistrationContext $context): void {
 		}, false);
 
 		$context->registerCapability(Capabilities::class);
+		$context->registerEventListener(AddMissingIndicesEvent::class, AddMissingIndicesListener::class);
 		$context->registerEventListener(LoadSidebar::class, LoadSidebarScripts::class);
 		$context->registerEventListener(UserDeletedEvent::class, UserDeleted::class);
 		$context->registerEventListener(PostLoginEvent::class, SetUserDefaults::class);
diff --git a/lib/Listener/AddMissingIndicesListener.php b/lib/Listener/AddMissingIndicesListener.php
new file mode 100644
index 000000000..aa2008466
--- /dev/null
+++ b/lib/Listener/AddMissingIndicesListener.php
@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Activity\Listener;
+
+use OCP\DB\Events\AddMissingIndicesEvent;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+
+/**
+ * @template-implements IEventListener<Event|AddMissingIndicesEvent>
+ */
+class AddMissingIndicesListener implements IEventListener {
+	#[\Override]
+
+	public function handle(Event $event): void {
+		if (!($event instanceof AddMissingIndicesEvent)) {
+			return;
+		}
+
+		$event->replaceIndex(
+			'activity',
+			['activity_object'],
+			'activity_object_user',
+			['affecteduser', 'object_type', 'object_id', 'timestamp'],
+			false,
+		);
+	}
+}
diff --git a/lib/Migration/Version2006Date20170808154933.php b/lib/Migration/Version2006Date20170808154933.php
index 7f91122cc..ed98e142a 100644
--- a/lib/Migration/Version2006Date20170808154933.php
+++ b/lib/Migration/Version2006Date20170808154933.php
@@ -95,6 +95,7 @@ public function changeSchema(IOutput $output, \Closure $schemaClosure, array $op
 			// FIXME Fixed install, see Version2006Date20170808155040: $table->addIndex(['affecteduser', 'app', 'timestamp'], 'activity_filter_app');
 			$table->addIndex(['affecteduser', 'type', 'app', 'timestamp'], 'activity_filter');
 			$table->addIndex(['object_type', 'object_id'], 'activity_object');
+			$table->addIndex(['affecteduser', 'object_type', 'object_id', 'timestamp'], 'activity_object_user');
 		}
 
 		if (!$schema->hasTable('activity_mq')) {