diff --git a/lib/private/Group/Manager.php b/lib/private/Group/Manager.php
index e3097e3d7ca..a0605767428 100644
--- a/lib/private/Group/Manager.php
+++ b/lib/private/Group/Manager.php
@@ -391,15 +391,6 @@ class Manager extends PublicEmitter implements IGroupManager {
 		}, $this->getUserGroups($user));
 	}
 
-	/**
-	 * get a list of all display names in a group
-	 *
-	 * @param string $gid
-	 * @param string $search
-	 * @param int $limit
-	 * @param int $offset
-	 * @return array an array of display names (value) and user ids (key)
-	 */
 	public function displayNamesInGroup($gid, $search = '', $limit = -1, $offset = 0) {
 		$group = $this->get($gid);
 		if (is_null($group)) {
diff --git a/lib/public/IGroupManager.php b/lib/public/IGroupManager.php
index 7e0575ad4be..93013e72891 100644
--- a/lib/public/IGroupManager.php
+++ b/lib/public/IGroupManager.php
@@ -101,7 +101,7 @@ interface IGroupManager {
 	 * @param string $search
 	 * @param int $limit
 	 * @param int $offset
-	 * @return array an array of display names (value) and user ids (key)
+	 * @return array<string, string> ['user id' => 'display name']
 	 * @since 8.0.0
 	 */
 	public function displayNamesInGroup($gid, $search = '', $limit = -1, $offset = 0);