diff --git a/php/federator/data/activitypub/common/collection.php b/php/federator/data/activitypub/common/collection.php
index 14b3a7c..fb847d6 100644
--- a/php/federator/data/activitypub/common/collection.php
+++ b/php/federator/data/activitypub/common/collection.php
@@ -10,7 +10,7 @@ namespace Federator\Data\ActivityPub\Common;
 
 class Collection extends APObject
 {
-    protected int $totalItems = 0;
+    protected int $totalItems = -1;
     private string $first = '';
     private string $last = '';
 
@@ -28,7 +28,7 @@ class Collection extends APObject
     {
         $return = parent::toObject();
         $return['type'] = 'Collection';
-        if ($this->totalItems > 0) {
+        if ($this->totalItems >= 0) {
             $return['totalItems'] = $this->totalItems;
         }
         if ($this->first !== '') {