diff --git a/includes/activitypub/handler/class-create.php b/includes/activitypub/handler/class-create.php
index 10e0864..9a860f4 100644
--- a/includes/activitypub/handler/class-create.php
+++ b/includes/activitypub/handler/class-create.php
@@ -70,6 +70,6 @@ class Create {
 			return;
 		}
 
-		$transmogrifier->save( $activity['object'] );
+		$transmogrifier->save( $activity['object'], $activity['actor'] );
 	}
 }
diff --git a/includes/activitypub/handler/class-update.php b/includes/activitypub/handler/class-update.php
index e106641..a1a6372 100644
--- a/includes/activitypub/handler/class-update.php
+++ b/includes/activitypub/handler/class-update.php
@@ -42,7 +42,6 @@ class Update {
 		}
 
 		// Check that we are actually following this actor.
-
 		if ( ! Event_Sources::actor_is_event_source( $activity['actor'] ) ) {
 			return;
 		}
@@ -67,6 +66,6 @@ class Update {
 			return;
 		}
 
-		$transmogrifier->save( $activity['object'] );
+		$transmogrifier->save( $activity['object'], $activity['actor'] );
 	}
 }
diff --git a/includes/activitypub/model/class-event-source.php b/includes/activitypub/model/class-event-source.php
index 494024d..f676146 100644
--- a/includes/activitypub/model/class-event-source.php
+++ b/includes/activitypub/model/class-event-source.php
@@ -97,7 +97,7 @@ class Event_Source extends Actor {
 	 * Get the Event Source by the ActivityPub ID.
 	 *
 	 * @param string $actor_id The ActivityPub actor ID.
-	 * @return Event_Source|false The Event Source Actor, if a WordPress Post representing it is found, false otherwise.
+	 * @return Event_Source|WP_Error|false The Event Source Actor, if a WordPress Post representing it is found, false otherwise.
 	 */
 	public static function get_by_id( $actor_id ) {
 		$post = self::get_wp_post_by_activitypub_actor_id( $actor_id );
diff --git a/includes/activitypub/transmogrifier/class-base.php b/includes/activitypub/transmogrifier/class-base.php
index 9a720c1..d85f878 100644
--- a/includes/activitypub/transmogrifier/class-base.php
+++ b/includes/activitypub/transmogrifier/class-base.php
@@ -26,7 +26,7 @@ defined( 'ABSPATH' ) || exit; // @codeCoverageIgnore
  */
 abstract class Base {
 	/**
-	 * The current GatherPress Event object.
+	 * The current Event object.
 	 *
 	 * @var Event
 	 */
@@ -40,11 +40,12 @@ abstract class Base {
 	abstract protected function save_event();
 
 	/**
-	 * Save the ActivityPub event object as GatherPress Event.
+	 * Save the ActivityPub event object within WordPress.
 	 *
-	 * @param array $activitypub_event The ActivityPub event as associative array.
+	 * @param array   $activitypub_event The ActivityPub event as associative array.
+	 * @param ?string $actor             The ActivityPub ID of the actor which we received the event from.
 	 */
-	public function save( $activitypub_event ) {
+	public function save( $activitypub_event, $actor ) {
 		$activitypub_event = Event::init_from_array( $activitypub_event );
 
 		if ( is_wp_error( $activitypub_event ) ) {
@@ -57,6 +58,7 @@ abstract class Base {
 
 		if ( $post_id ) {
 			update_post_meta( $post_id, '_event_bridge_for_activitypub_is_remote_cached', true );
+			update_post_meta( $post_id, '_event_bridge_for_activitypub_event_source', sanitize_url( $actor ) );
 			update_post_meta( $post_id, 'activitypub_content_visibility', constant( 'ACTIVITYPUB_CONTENT_VISIBILITY_LOCAL' ) ?? '' );
 		}
 	}