diff --git a/lib/Chat/AutoComplete/Sorter.php b/lib/Chat/AutoComplete/Sorter.php
index 7514f4db4..802556c0f 100644
--- a/lib/Chat/AutoComplete/Sorter.php
+++ b/lib/Chat/AutoComplete/Sorter.php
@@ -22,10 +22,18 @@
 namespace OCA\Spreed\Chat\AutoComplete;
 
 
+use OCA\Spreed\Chat\CommentsManager;
 use OCP\Collaboration\AutoComplete\ISorter;
 
 class Sorter implements ISorter {
 
+	/** @var CommentsManager */
+	protected $commentsManager;
+
+	public function __construct(CommentsManager $commentsManager) {
+		$this->commentsManager = $commentsManager;
+	}
+
 	/**
 	 * @return string The ID of the sorter, e.g. commenters
 	 * @since 13.0.0
@@ -42,6 +50,25 @@ class Sorter implements ISorter {
 	 * @since 13.0.0
 	 */
 	public function sort(array &$sortArray, array $context) {
-		// TODO: Implement sort() method.
+		foreach ($sortArray as $type => &$byType) {
+			$lastComments = $this->commentsManager->getLastCommentDateByActor(
+				$context['itemType'],
+				$context['itemId'],
+				'comment',
+				$type,
+				array_map(function($suggestion) {
+					return $suggestion['value']['shareWith'];
+			}, $byType));
+
+			usort($byType, function ($a, $b) use ($lastComments) {
+				if (!isset($lastComments[$b['value']['shareWith']])) {
+					return -1;
+				}
+				if (!isset($lastComments[$a['value']['shareWith']])) {
+					return 1;
+				}
+				return $lastComments[$a['value']['shareWith']] - $lastComments[$b['value']['shareWith']];
+			});
+		}
 	}
 }
diff --git a/lib/Chat/CommentsManager.php b/lib/Chat/CommentsManager.php
index a0ff0a3b3..85cb24ab8 100644
--- a/lib/Chat/CommentsManager.php
+++ b/lib/Chat/CommentsManager.php
@@ -143,4 +143,41 @@ class CommentsManager extends Manager {
 
 		return null;
 	}
+
+	/**
+	 * @param string $objectType
+	 * @param string $objectId
+	 * @param string $verb
+	 * @param string $actorType
+	 * @param string[] $actors
+	 * @return array
+	 */
+	public function getLastCommentDateByActor(
+		$objectType,
+		$objectId,
+		$verb,
+		$actorType,
+		array $actors
+	) {
+		$lastComments = [];
+
+		$query = $this->dbConn->getQueryBuilder();
+		$query->select('actor_id')
+			->selectAlias($query->createFunction('MAX(' . $query->getColumnName('creation_timestamp') . ')'), 'last_comment')
+			->from('comments')
+			->where($query->expr()->eq('object_type', $query->createNamedParameter($objectType)))
+			->andWhere($query->expr()->eq('object_id', $query->createNamedParameter($objectId)))
+			->andWhere($query->expr()->eq('verb', $query->createNamedParameter($verb)))
+			->andWhere($query->expr()->eq('actor_type', $query->createNamedParameter($actorType)))
+			->andWhere($query->expr()->in('actor_id', $query->createNamedParameter($actors, IQueryBuilder::PARAM_STR_ARRAY)))
+			->groupBy('actor_id');
+
+		$result = $query->execute();
+		while ($row = $result->fetch()) {
+			$lastComments[$row['actor_id']] = new \DateTime($row['latest_comment']);
+		}
+		$result->closeCursor();
+
+		return $lastComments;
+	}
 }
diff --git a/lib/Controller/ChatController.php b/lib/Controller/ChatController.php
index 2c1839c2d..0b108bddc 100644
--- a/lib/Controller/ChatController.php
+++ b/lib/Controller/ChatController.php
@@ -25,6 +25,7 @@ namespace OCA\Spreed\Controller;
 
 use OC\Collaboration\Collaborators\SearchResult;
 use OCA\Spreed\Chat\AutoComplete\SearchPlugin;
+use OCA\Spreed\Chat\AutoComplete\Sorter;
 use OCA\Spreed\Chat\ChatManager;
 use OCA\Spreed\Chat\RichMessageHelper;
 use OCA\Spreed\Exceptions\ParticipantNotFoundException;
@@ -325,6 +326,7 @@ class ChatController extends OCSController {
 		unset($results['exact']);
 		$results = array_merge_recursive($exactMatches, $results);
 
+		$this->autoCompleteManager->registerSorter(Sorter::class);
 		$this->autoCompleteManager->runSorters(['talk_chat_participants'], $results, [
 			'itemType' => 'chat',
 			'itemId' => $room->getId(),