diff --git a/composer.lock b/composer.lock
index 7973167762..9230bb4db9 100644
--- a/composer.lock
+++ b/composer.lock
@@ -332,11 +332,11 @@
         },
         {
             "name": "friendica/json-ld",
-            "version": "1.0.0",
+            "version": "1.1.1",
             "source": {
                 "type": "git",
                 "url": "https://git.friendi.ca/friendica/php-json-ld",
-                "reference": "a9ac64daf01cfd97e80c36a5104247d37c0ae5ef"
+                "reference": "ca3916d10d2ad9073b3b1eae383978dbe828e1e1"
             },
             "require": {
                 "ext-json": "*",
@@ -355,11 +355,11 @@
                 {
                     "name": "Digital Bazaar, Inc.",
                     "email": "support@digitalbazaar.com",
-                    "url": "http://digitalbazaar.com/"
+                    "homepage": "http://digitalbazaar.com/"
                 },
                 {
                     "name": "Friendica Team",
-                    "url": "https://friendi.ca/"
+                    "homepage": "https://friendi.ca/"
                 }
             ],
             "description": "A JSON-LD Processor and API implementation in PHP.",
@@ -372,7 +372,7 @@
                 "Semantic Web",
                 "jsonld"
             ],
-            "time": "2018-09-28T00:01:12+00:00"
+            "time": "2018-10-08T20:41:00+00:00"
         },
         {
             "name": "fxp/composer-asset-plugin",
diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index 32cfcc6cb0..a85123817a 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -18,6 +18,9 @@ use Friendica\Protocol\ActivityPub;
 
 /**
  * ActivityPub Protocol class
+ *
+ * To-Do:
+ * - Store Diaspora signature
  */
 class Processor
 {
@@ -194,7 +197,14 @@ class Processor
 		$item['network'] = Protocol::ACTIVITYPUB;
 		$item['private'] = !in_array(0, $activity['receiver']);
 		$item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
-		$item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, true);
+
+		if (empty($activity['thread-completion'])) {
+			$item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, true);
+		} else {
+			logger('Ignoring actor because of thread completion.', LOGGER_DEBUG);
+			$item['owner-id'] = $item['author-id'];
+		}
+
 		$item['uri'] = $activity['id'];
 		$item['created'] = $activity['published'];
 		$item['edited'] = $activity['updated'];
@@ -261,6 +271,9 @@ class Processor
 		$activity['type'] = 'Create';
 
 		$ldactivity = JsonLD::compact($activity);
+
+		$ldactivity['thread-completion'] = true;
+
 		ActivityPub\Receiver::processActivity($ldactivity);
 		logger('Activity ' . $url . ' had been fetched and processed.');
 	}
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index 1dac0bb827..f371eede7f 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -268,6 +268,11 @@ class Receiver
 			return;
 		}
 
+		// Internal flag for thread completion. See Processor.php
+		if (!empty($activity['thread-completion'])) {
+			$object_data['thread-completion'] = $activity['thread-completion'];
+		}
+
 		switch ($type) {
 			case 'as:Create':
 			case 'as:Announce':
diff --git a/src/Worker/Notifier.php b/src/Worker/Notifier.php
index b57c81db77..6bfd2bc3b3 100644
--- a/src/Worker/Notifier.php
+++ b/src/Worker/Notifier.php
@@ -103,9 +103,9 @@ class Notifier
 
 			$inboxes = ActivityPub\Transmitter::fetchTargetInboxesforUser(0);
 			foreach ($inboxes as $inbox) {
-				logger('Account removal for user ' . $uid . ' to ' . $inbox .' via ActivityPub', LOGGER_DEBUG);
+				logger('Account removal for user ' . $item_id . ' to ' . $inbox .' via ActivityPub', LOGGER_DEBUG);
 				Worker::add(['priority' => $a->queue['priority'], 'created' => $a->queue['created'], 'dont_fork' => true],
-					'APDelivery', Delivery::REMOVAL, '', $inbox, $uid);
+					'APDelivery', Delivery::REMOVAL, '', $inbox, $item_id);
 			}
 
 			return;