diff --git a/Events.php b/Events.php
index 88479d0..cd38faf 100644
--- a/Events.php
+++ b/Events.php
@@ -143,8 +143,7 @@ public static function onSampleDataInstall($event)
 
         $comment = new \humhub\modules\comment\models\Comment();
         $comment->message = Yii::t('PollsModule.base', "Why don't we go to Bemelmans Bar?");
-        $comment->object_model = $poll->className();
-        $comment->object_id = $poll->getPrimaryKey();
+        $comment->content_id = $poll->content->id;
         $comment->save();
 
         // Switch Identity
@@ -155,8 +154,7 @@ public static function onSampleDataInstall($event)
 
         $comment = new \humhub\modules\comment\models\Comment();
         $comment->message = Yii::t('PollsModule.base', "Again? :weary:");
-        $comment->object_model = $poll->className();
-        $comment->object_id = $poll->getPrimaryKey();
+        $comment->content_id = $poll->content->id;
         $comment->save();
 
         // Switch Identity
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 2de21b7..3c26a60 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -1,6 +1,10 @@
 Changelog
 =========
 
+1.5.1 (Unreleased)
+------------------
+- Fix #175: Error creating installer sample content (comment no longer uses removed `object_model`/`object_id` properties)
+
 1.5.0 (June 5, 2026)
 --------------------
 - Enh #174: Update for HumHub 1.19