diff --git a/mod/item.php b/mod/item.php
index 9828d1acb2..3869ea9107 100644
--- a/mod/item.php
+++ b/mod/item.php
@@ -605,8 +605,7 @@ function item_post(App $a) {
 	$datarray['pubmail']       = $pubmail_enabled;
 	$datarray['attach']        = $attachments;
 
-	// This is not a bug. The item store function changes 'parent-uri' to 'thr-parent' and fetches 'parent-uri' new. (We should change this)
-	$datarray['parent-uri']    = $thr_parent_uri;
+	$datarray['thr-parent']    = $thr_parent_uri;
 
 	$datarray['postopts']      = $postopts;
 	$datarray['origin']        = $origin;
@@ -627,7 +626,7 @@ function item_post(App $a) {
 	// This field is for storing the raw conversation data
 	$datarray['protocol'] = Conversation::PARCEL_DFRN;
 
-	$conversation = DBA::selectFirst('conversation', ['conversation-uri', 'conversation-href'], ['item-uri' => $datarray['parent-uri']]);
+	$conversation = DBA::selectFirst('conversation', ['conversation-uri', 'conversation-href'], ['item-uri' => $datarray['thr-parent']]);
 	if (DBA::isResult($conversation)) {
 		if ($conversation['conversation-uri'] != '') {
 			$datarray['conversation-uri'] = $conversation['conversation-uri'];
diff --git a/mod/tagger.php b/mod/tagger.php
index 86a6ff69f3..63e7f2ca80 100644
--- a/mod/tagger.php
+++ b/mod/tagger.php
@@ -136,7 +136,7 @@ EOT;
 	$arr['wall'] = $item['wall'];
 	$arr['gravity'] = GRAVITY_COMMENT;
 	$arr['parent'] = $item['id'];
-	$arr['parent-uri'] = $item['uri'];
+	$arr['thr-parent'] = $item['uri'];
 	$arr['owner-name'] = $item['author-name'];
 	$arr['owner-link'] = $item['author-link'];
 	$arr['owner-avatar'] = $item['author-avatar'];
diff --git a/src/Protocol/DFRN.php b/src/Protocol/DFRN.php
index 11c4e3a14d..165a63c7cb 100644
--- a/src/Protocol/DFRN.php
+++ b/src/Protocol/DFRN.php
@@ -438,7 +438,7 @@ class DFRN
 		$mail->appendChild($sender);
 
 		XML::addElement($doc, $mail, "dfrn:id", $item['uri']);
-		XML::addElement($doc, $mail, "dfrn:in-reply-to", $item['parent-uri']);
+		XML::addElement($doc, $mail, "dfrn:in-reply-to", $item['thr-parent']);
 		XML::addElement($doc, $mail, "dfrn:sentdate", DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM));
 		XML::addElement($doc, $mail, "dfrn:subject", $item['title']);
 		XML::addElement($doc, $mail, "dfrn:content", $item['body']);
@@ -956,10 +956,9 @@ class DFRN
 		$entry->appendChild($dfrnowner);
 
 		if ($item['gravity'] != GRAVITY_PARENT) {
-			$parent_item = (($item['thr-parent']) ? $item['thr-parent'] : $item['parent-uri']);
-			$parent = Item::selectFirst(['guid', 'plink'], ['uri' => $parent_item, 'uid' => $item['uid']]);
+			$parent = Item::selectFirst(['guid', 'plink'], ['uri' => $item['thr-parent'], 'uid' => $item['uid']]);
 			if (DBA::isResult($parent)) {
-				$attributes = ["ref" => $parent_item, "type" => "text/html",
+				$attributes = ["ref" => $item['thr-parent'], "type" => "text/html",
 					"href" => $parent['plink'],
 					"dfrn:diaspora_guid" => $parent['guid']];
 				XML::addElement($doc, $entry, "thr:in-reply-to", "", $attributes);
@@ -971,7 +970,7 @@ class DFRN
 		$conversation_uri = $conversation_href;
 
 		if (isset($parent_item)) {
-			$conversation = DBA::selectFirst('conversation', ['conversation-uri', 'conversation-href'], ['item-uri' => $item['parent-uri']]);
+			$conversation = DBA::selectFirst('conversation', ['conversation-uri', 'conversation-href'], ['item-uri' => $item['thr-parent']]);
 			if (DBA::isResult($conversation)) {
 				if ($conversation['conversation-uri'] != '') {
 					$conversation_uri = $conversation['conversation-uri'];
@@ -1768,7 +1767,7 @@ class DFRN
 		$msg["from-photo"] = XML::getFirstValue($xpath, "dfrn:sender/dfrn:avatar/text()", $mail);
 		$msg["contact-id"] = $importer["id"];
 		$msg["uri"] = XML::getFirstValue($xpath, "dfrn:id/text()", $mail);
-		$msg["parent-uri"] = XML::getFirstValue($xpath, "dfrn:in-reply-to/text()", $mail);
+		$msg["thr-parent"] = XML::getFirstValue($xpath, "dfrn:in-reply-to/text()", $mail);
 		$msg["created"] = DateTimeFormat::utc(XML::getFirstValue($xpath, "dfrn:sentdate/text()", $mail));
 		$msg["title"] = XML::getFirstValue($xpath, "dfrn:subject/text()", $mail);
 		$msg["body"] = XML::getFirstValue($xpath, "dfrn:content/text()", $mail);
@@ -1918,7 +1917,7 @@ class DFRN
 	 */
 	private static function getEntryType($importer, $item)
 	{
-		if ($item["parent-uri"] != $item["uri"]) {
+		if ($item["thr-parent"] != $item["uri"]) {
 			$community = false;
 
 			if ($importer["page-flags"] == User::PAGE_FLAGS_COMMUNITY || $importer["page-flags"] == User::PAGE_FLAGS_PRVGROUP) {
@@ -1934,18 +1933,18 @@ class DFRN
 
 			$is_a_remote_action = false;
 
-			$parent = Item::selectFirst(['parent-uri'], ['uri' => $item["parent-uri"]]);
+			$parent = Item::selectFirst(['thr-parent'], ['uri' => $item["thr-parent"]]);
 			if (DBA::isResult($parent)) {
 				$r = q(
 					"SELECT `item`.`forum_mode`, `item`.`wall` FROM `item`
 					INNER JOIN `contact` ON `contact`.`id` = `item`.`contact-id`
-					WHERE `item`.`uri` = '%s' AND (`item`.`parent-uri` = '%s' OR `item`.`thr-parent` = '%s')
+					WHERE `item`.`uri` = '%s' AND (`item`.`thr-parent` = '%s' OR `item`.`thr-parent` = '%s')
 					AND `item`.`uid` = %d
 					$sql_extra
 					LIMIT 1",
-					DBA::escape($parent["parent-uri"]),
-					DBA::escape($parent["parent-uri"]),
-					DBA::escape($parent["parent-uri"]),
+					DBA::escape($parent["thr-parent"]),
+					DBA::escape($parent["thr-parent"]),
+					DBA::escape($parent["thr-parent"]),
 					intval($importer["importer_uid"])
 				);
 				if (DBA::isResult($r)) {
@@ -2008,7 +2007,7 @@ class DFRN
 			if ($Blink && Strings::compareLink($Blink, DI::baseUrl() . "/profile/" . $importer["nickname"])) {
 				$author = DBA::selectFirst('contact', ['name', 'thumb', 'url'], ['id' => $item['author-id']]);
 
-				$parent = Item::selectFirst(['id'], ['uri' => $item['parent-uri'], 'uid' => $importer["importer_uid"]]);
+				$parent = Item::selectFirst(['id'], ['uri' => $item['thr-parent'], 'uid' => $importer["importer_uid"]]);
 				$item['parent'] = $parent['id'];
 
 				// send a notification
@@ -2090,15 +2089,15 @@ class DFRN
 				$is_like = true;
 				$item["gravity"] = GRAVITY_ACTIVITY;
 				// only one like or dislike per person
-				// splitted into two queries for performance issues
+				// split into two queries for performance issues
 				$condition = ['uid' => $item["uid"], 'author-id' => $item["author-id"], 'gravity' => GRAVITY_ACTIVITY,
-					'verb' => $item["verb"], 'parent-uri' => $item["parent-uri"]];
+					'verb' => $item['verb'], 'parent-uri' => $item['thr-parent']];
 				if (Item::exists($condition)) {
 					return false;
 				}
 
 				$condition = ['uid' => $item["uid"], 'author-id' => $item["author-id"], 'gravity' => GRAVITY_ACTIVITY,
-					'verb' => $item["verb"], 'thr-parent' => $item["parent-uri"]];
+					'verb' => $item['verb'], 'thr-parent' => $item['thr-parent']];
 				if (Item::exists($condition)) {
 					return false;
 				}
@@ -2370,19 +2369,19 @@ class DFRN
 		}
 
 		// Is it a reply or a top level posting?
-		$item["parent-uri"] = $item["uri"];
+		$item['thr-parent'] = $item['uri'];
 
 		$inreplyto = $xpath->query("thr:in-reply-to", $entry);
 		if (is_object($inreplyto->item(0))) {
 			foreach ($inreplyto->item(0)->attributes as $attributes) {
 				if ($attributes->name == "ref") {
-					$item["parent-uri"] = $attributes->textContent;
+					$item['thr-parent'] = $attributes->textContent;
 				}
 			}
 		}
 
 		// Check if the message is wanted
-		if (($importer["importer_uid"] == 0) && ($item['uri'] == $item['parent-uri'])) {
+		if (($importer['importer_uid'] == 0) && ($item['uri'] == $item['thr-parent'])) {
 			if (!self::isSolicitedMessage($item)) {
 				DBA::delete('item-uri', ['uri' => $item['uri']]);
 				return 403;
@@ -2760,7 +2759,7 @@ class DFRN
 
 		// check that the message originated elsewhere and is a top-level post
 
-		if ($item['wall'] || $item['origin'] || ($item['uri'] != $item['parent-uri'])) {
+		if ($item['wall'] || $item['origin'] || ($item['uri'] != $item['thr-parent'])) {
 			return false;
 		}
 
diff --git a/src/Protocol/Diaspora.php b/src/Protocol/Diaspora.php
index 8c93d7c0f2..04d076c03a 100644
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@@ -1697,9 +1697,9 @@ class Diaspora
 
 		if (isset($data->thread_parent_guid)) {
 			$thread_parent_guid = Strings::escapeTags(XML::unescape($data->thread_parent_guid));
-			$thr_uri = self::getUriFromGuid("", $thread_parent_guid, true);
+			$thr_parent = self::getUriFromGuid("", $thread_parent_guid, true);
 		} else {
-			$thr_uri = "";
+			$thr_parent = "";
 		}
 
 		$contact = self::allowedContactByHandle($importer, $sender, true);
@@ -1712,8 +1712,8 @@ class Diaspora
 			return true;
 		}
 
-		$parent_item = self::parentItem($importer["uid"], $parent_guid, $author, $contact);
-		if (!$parent_item) {
+		$toplevel_parent_item = self::parentItem($importer["uid"], $parent_guid, $author, $contact);
+		if (!$toplevel_parent_item) {
 			return false;
 		}
 
@@ -1754,11 +1754,8 @@ class Diaspora
 		$datarray["verb"] = Activity::POST;
 		$datarray["gravity"] = GRAVITY_COMMENT;
 
-		if ($thr_uri != "") {
-			$datarray["parent-uri"] = $thr_uri;
-		} else {
-			$datarray["parent-uri"] = $parent_item["uri"];
-		}
+		$datarray['thr-parent'] = $thr_parent ?: $toplevel_parent_item['uri'];
+		$datarray['parent-uri'] = $toplevel_parent_item['uri'];
 
 		$datarray["object-type"] = Activity\ObjectType::COMMENT;
 
@@ -1767,7 +1764,7 @@ class Diaspora
 
 		$datarray["changed"] = $datarray["created"] = $datarray["edited"] = $created_at;
 
-		$datarray["plink"] = self::plink($author, $guid, $parent_item['guid']);
+		$datarray["plink"] = self::plink($author, $guid, $toplevel_parent_item['guid']);
 		$body = Markdown::toBBCode($text);
 
 		$datarray["body"] = self::replacePeopleGuid($body, $person["url"]);
@@ -1779,7 +1776,7 @@ class Diaspora
 
 		// If we are the origin of the parent we store the original data.
 		// We notify our followers during the item storage.
-		if ($parent_item["origin"]) {
+		if ($toplevel_parent_item["origin"]) {
 			$datarray['diaspora_signed_text'] = json_encode($data);
 		}
 
@@ -1953,8 +1950,8 @@ class Diaspora
 			return true;
 		}
 
-		$parent_item = self::parentItem($importer["uid"], $parent_guid, $author, $contact);
-		if (!$parent_item) {
+		$toplevel_parent_item = self::parentItem($importer["uid"], $parent_guid, $author, $contact);
+		if (!$toplevel_parent_item) {
 			return false;
 		}
 
@@ -1991,7 +1988,7 @@ class Diaspora
 
 		$datarray["verb"] = $verb;
 		$datarray["gravity"] = GRAVITY_ACTIVITY;
-		$datarray["parent-uri"] = $parent_item["uri"];
+		$datarray['thr-parent'] = $toplevel_parent_item['uri'];
 
 		$datarray["object-type"] = Activity\ObjectType::NOTE;
 
@@ -2001,11 +1998,11 @@ class Diaspora
 		$datarray["changed"] = $datarray["created"] = $datarray["edited"] = DateTimeFormat::utcNow();
 
 		// like on comments have the comment as parent. So we need to fetch the toplevel parent
-		if ($parent_item['gravity'] != GRAVITY_PARENT) {
-			$toplevel = Item::selectFirst(['origin'], ['id' => $parent_item['parent']]);
+		if ($toplevel_parent_item['gravity'] != GRAVITY_PARENT) {
+			$toplevel = Item::selectFirst(['origin'], ['id' => $toplevel_parent_item['parent']]);
 			$origin = $toplevel["origin"];
 		} else {
-			$origin = $parent_item["origin"];
+			$origin = $toplevel_parent_item["origin"];
 		}
 
 		// If we are the origin of the parent we store the original data.
@@ -2116,16 +2113,16 @@ class Diaspora
 			return true;
 		}
 
-		$parent_item = self::parentItem($importer["uid"], $parent_guid, $author, $contact);
-		if (!$parent_item) {
+		$toplevel_parent_item = self::parentItem($importer["uid"], $parent_guid, $author, $contact);
+		if (!$toplevel_parent_item) {
 			return false;
 		}
 
-		if (!$parent_item['origin']) {
+		if (!$toplevel_parent_item['origin']) {
 			Logger::info('Not our origin. Participation is ignored', ['parent_guid' => $parent_guid, 'guid' => $guid, 'author' => $author]);
 		}
 
-		if (!in_array($parent_item['private'], [Item::PUBLIC, Item::UNLISTED])) {
+		if (!in_array($toplevel_parent_item['private'], [Item::PUBLIC, Item::UNLISTED])) {
 			Logger::info('Item is not public, participation is ignored', ['parent_guid' => $parent_guid, 'guid' => $guid, 'author' => $author]);
 			return false;
 		}
@@ -2155,7 +2152,8 @@ class Diaspora
 
 		$datarray["verb"] = Activity::FOLLOW;
 		$datarray["gravity"] = GRAVITY_ACTIVITY;
-		$datarray["parent-uri"] = $parent_item["uri"];
+		$datarray['thr-parent'] = $toplevel_parent_item['uri'];
+		$datarray['parent-uri'] = $toplevel_parent_item['parent-uri'];
 
 		$datarray["object-type"] = Activity\ObjectType::NOTE;
 
@@ -2170,7 +2168,7 @@ class Diaspora
 
 		// Send all existing comments and likes to the requesting server
 		$comments = Item::select(['id', 'uri-id', 'parent-author-network', 'author-network', 'verb'],
-			['parent' => $parent_item['id'], 'gravity' => [GRAVITY_COMMENT, GRAVITY_ACTIVITY]]);
+			['parent' => $toplevel_parent_item['id'], 'gravity' => [GRAVITY_COMMENT, GRAVITY_ACTIVITY]]);
 		while ($comment = Item::fetch($comments)) {
 			if (in_array($comment['verb'], [Activity::FOLLOW, Activity::TAG])) {
 				Logger::info('participation messages are not relayed', ['item' => $comment['id']]);
@@ -2547,7 +2545,8 @@ class Diaspora
 
 		$datarray['guid'] = $parent['guid'] . '-' . $guid;
 		$datarray['uri'] = self::getUriFromGuid($author, $datarray['guid']);
-		$datarray['parent-uri'] = $parent['uri'];
+		$datarray['thr-parent'] = $parent['uri'];
+		$datarray['parent-uri'] = $parent['parent-uri'];
 
 		$datarray['verb'] = $datarray['body'] = Activity::ANNOUNCE;
 		$datarray['gravity'] = GRAVITY_ACTIVITY;
@@ -2618,7 +2617,7 @@ class Diaspora
 		$datarray["owner-id"] = $datarray["author-id"];
 
 		$datarray["guid"] = $guid;
-		$datarray["uri"] = $datarray["parent-uri"] = self::getUriFromGuid($author, $guid);
+		$datarray["uri"] = $datarray["thr-parent"] = self::getUriFromGuid($author, $guid);
 		$datarray['uri-id'] = ItemURI::insert(['uri' => $datarray['uri'], 'guid' => $datarray['guid']]);
 
 		$datarray["verb"] = Activity::POST;
@@ -2703,7 +2702,7 @@ class Diaspora
 		}
 
 		// Fetch items that are about to be deleted
-		$fields = ['uid', 'id', 'parent', 'parent-uri', 'author-link', 'file'];
+		$fields = ['uid', 'id', 'parent', 'author-link', 'file'];
 
 		// When we receive a public retraction, we delete every item that we find.
 		if ($importer['uid'] == 0) {
@@ -2872,7 +2871,7 @@ class Diaspora
 		$datarray = [];
 
 		$datarray["guid"] = $guid;
-		$datarray["uri"] = $datarray["parent-uri"] = self::getUriFromGuid($author, $guid);
+		$datarray["uri"] = $datarray["thr-parent"] = self::getUriFromGuid($author, $guid);
 		$datarray['uri-id'] = ItemURI::insert(['uri' => $datarray['uri'], 'guid' => $datarray['guid']]);
 
 		// Attach embedded pictures to the body
@@ -3681,12 +3680,12 @@ class Diaspora
 	 */
 	private static function constructLike(array $item, array $owner)
 	{
-		$parent = Item::selectFirst(['guid', 'uri', 'parent-uri'], ['uri' => $item["thr-parent"]]);
+		$parent = Item::selectFirst(['guid', 'uri', 'thr-parent'], ['uri' => $item["thr-parent"]]);
 		if (!DBA::isResult($parent)) {
 			return false;
 		}
 
-		$target_type = ($parent["uri"] === $parent["parent-uri"] ? "Post" : "Comment");
+		$target_type = ($parent["uri"] === $parent["thr-parent"] ? "Post" : "Comment");
 		$positive = null;
 		if ($item['verb'] === Activity::LIKE) {
 			$positive = "true";
@@ -3713,7 +3712,7 @@ class Diaspora
 	 */
 	private static function constructAttend(array $item, array $owner)
 	{
-		$parent = Item::selectFirst(['guid', 'uri', 'parent-uri'], ['uri' => $item["thr-parent"]]);
+		$parent = Item::selectFirst(['guid'], ['uri' => $item['thr-parent']]);
 		if (!DBA::isResult($parent)) {
 			return false;
 		}
@@ -4242,10 +4241,7 @@ class Diaspora
 			return false;
 		}
 
-		// This is a workaround for the behaviour of the "insert" function, see mod/item.php
-		$item['thr-parent'] = $item['parent-uri'];
-
-		$parent = Item::selectFirst(['parent-uri'], ['uri' => $item['parent-uri']]);
+		$parent = Item::selectFirst(['parent-uri'], ['uri' => $item['thr-parent']]);
 		if (!DBA::isResult($parent)) {
 			return;
 		}
diff --git a/src/Protocol/Feed.php b/src/Protocol/Feed.php
index fee765f25b..c7d19a996d 100644
--- a/src/Protocol/Feed.php
+++ b/src/Protocol/Feed.php
@@ -354,7 +354,7 @@ class Feed
 
 			$item["plink"] = DI::httpRequest()->finalUrl($item["plink"]);
 
-			$item["parent-uri"] = $item["uri"];
+			$item["thr-parent"] = $item["uri"];
 
 			$item["title"] = XML::getFirstNodeValue($xpath, 'atom:title/text()', $entry);
 
@@ -602,6 +602,7 @@ class Feed
 			if ($notify) {
 				$item['guid'] = Item::guidFromUri($orig_plink, DI::baseUrl()->getHostname());
 				unset($item['uri']);
+				unset($item['thr-parent']);
 				unset($item['parent-uri']);
 
 				// Set the delivery priority for "remote self" to "medium"
@@ -1108,9 +1109,8 @@ class Feed
 
 		if ($item['gravity'] != GRAVITY_PARENT) {
 			$parent = Item::selectFirst(['guid', 'author-link', 'owner-link'], ['id' => $item['parent']]);
-			$parent_item = (($item['thr-parent']) ? $item['thr-parent'] : $item['parent-uri']);
 
-			$thrparent = Item::selectFirst(['guid', 'author-link', 'owner-link', 'plink'], ['uid' => $owner["uid"], 'uri' => $parent_item]);
+			$thrparent = Item::selectFirst(['guid', 'author-link', 'owner-link', 'plink'], ['uid' => $owner["uid"], 'uri' => $item['thr-parent']]);
 
 			if (DBA::isResult($thrparent)) {
 				$mentioned[$thrparent["author-link"]] = $thrparent["author-link"];
@@ -1123,7 +1123,7 @@ class Feed
 			}
 
 			$attributes = [
-					"ref" => $parent_item,
+					"ref" => $item['thr-parent'],
 					"href" => $parent_plink];
 			XML::addElement($doc, $entry, "thr:in-reply-to", "", $attributes);
 
diff --git a/src/Protocol/OStatus.php b/src/Protocol/OStatus.php
index e394877b35..9218f26651 100644
--- a/src/Protocol/OStatus.php
+++ b/src/Protocol/OStatus.php
@@ -482,7 +482,7 @@ class OStatus
 				Logger::log("Favorite ".$orig_uri." ".print_r($item, true));
 
 				$item["verb"] = Activity::LIKE;
-				$item["parent-uri"] = $orig_uri;
+				$item["thr-parent"] = $orig_uri;
 				$item["gravity"] = GRAVITY_ACTIVITY;
 				$item["object-type"] = Activity\ObjectType::NOTE;
 			}
@@ -495,7 +495,7 @@ class OStatus
 			self::processPost($xpath, $entry, $item, $importer);
 
 			if ($initialize && (count(self::$itemlist) > 0)) {
-				if (self::$itemlist[0]['uri'] == self::$itemlist[0]['parent-uri']) {
+				if (self::$itemlist[0]['uri'] == self::$itemlist[0]['thr-parent']) {
 					// We will import it everytime, when it is started by our contacts
 					$valid = Contact::isSharingByURL(self::$itemlist[0]['author-link'], self::$itemlist[0]['uid']);
 
@@ -523,9 +523,9 @@ class OStatus
 					}
 				} else {
 					// But we will only import complete threads
-					$valid = Item::exists(['uid' => $importer["uid"], 'uri' => self::$itemlist[0]['parent-uri']]);
+					$valid = Item::exists(['uid' => $importer["uid"], 'uri' => self::$itemlist[0]['thr-parent']]);
 					if ($valid) {
-						Logger::log("Item with uri ".self::$itemlist[0]["uri"]." belongs to parent ".self::$itemlist[0]['parent-uri']." of user ".$importer["uid"].". It will be imported.", Logger::DEBUG);
+						Logger::log("Item with uri ".self::$itemlist[0]["uri"]." belongs to parent ".self::$itemlist[0]['thr-parent']." of user ".$importer["uid"].". It will be imported.", Logger::DEBUG);
 					}
 				}
 
@@ -621,7 +621,7 @@ class OStatus
 		if (is_object($inreplyto->item(0))) {
 			foreach ($inreplyto->item(0)->attributes as $attributes) {
 				if ($attributes->name == "ref") {
-					$item["parent-uri"] = $attributes->textContent;
+					$item["thr-parent"] = $attributes->textContent;
 				}
 				if ($attributes->name == "href") {
 					$related = $attributes->textContent;
@@ -702,16 +702,16 @@ class OStatus
 			self::fetchConversation($item['conversation-href'], $item['conversation-uri']);
 		}
 
-		if (isset($item["parent-uri"])) {
-			if (!Item::exists(['uid' => $importer["uid"], 'uri' => $item['parent-uri']])) {
+		if (isset($item["thr-parent"])) {
+			if (!Item::exists(['uid' => $importer["uid"], 'uri' => $item['thr-parent']])) {
 				if ($related != '') {
-					self::fetchRelated($related, $item["parent-uri"], $importer);
+					self::fetchRelated($related, $item["thr-parent"], $importer);
 				}
 			} else {
 				Logger::log('Reply with URI '.$item["uri"].' already existed for user '.$importer["uid"].'.', Logger::DEBUG);
 			}
 		} else {
-			$item["parent-uri"] = $item["uri"];
+			$item["thr-parent"] = $item["uri"];
 			$item["gravity"] = GRAVITY_PARENT;
 		}
 
@@ -1074,7 +1074,7 @@ class OStatus
 		if (is_object($inreplyto->item(0))) {
 			foreach ($inreplyto->item(0)->attributes as $attributes) {
 				if ($attributes->name == "ref") {
-					$item["parent-uri"] = $attributes->textContent;
+					$item["thr-parent"] = $attributes->textContent;
 				}
 			}
 		}
@@ -1126,8 +1126,8 @@ class OStatus
 						break;
 					case "related":
 						if ($item["object-type"] != Activity\ObjectType::BOOKMARK) {
-							if (!isset($item["parent-uri"])) {
-								$item["parent-uri"] = $attribute['href'];
+							if (!isset($item["thr-parent"])) {
+								$item["thr-parent"] = $attribute['href'];
 							}
 							$link_data['related'] = $attribute['href'];
 						} else {
@@ -1934,9 +1934,8 @@ class OStatus
 
 		if ($item['gravity'] != GRAVITY_PARENT) {
 			$parent = Item::selectFirst(['guid', 'author-link', 'owner-link'], ['id' => $item['parent']]);
-			$parent_item = (($item['thr-parent']) ? $item['thr-parent'] : $item['parent-uri']);
 
-			$thrparent = Item::selectFirst(['guid', 'author-link', 'owner-link', 'plink'], ['uid' => $owner["uid"], 'uri' => $parent_item]);
+			$thrparent = Item::selectFirst(['guid', 'author-link', 'owner-link', 'plink'], ['uid' => $owner["uid"], 'uri' => $item['thr-parent']]);
 
 			if (DBA::isResult($thrparent)) {
 				$mentioned[$thrparent["author-link"]] = $thrparent["author-link"];
@@ -1949,7 +1948,7 @@ class OStatus
 			}
 
 			$attributes = [
-					"ref" => $parent_item,
+					"ref" => $item['thr-parent'],
 					"href" => $parent_plink];
 			XML::addElement($doc, $entry, "thr:in-reply-to", "", $attributes);
 
@@ -1960,7 +1959,7 @@ class OStatus
 		}
 
 		if (intval($item['parent']) > 0) {
-			$conversation_href = $conversation_uri = str_replace('/objects/', '/context/', $item['parent-uri']);
+			$conversation_href = $conversation_uri = str_replace('/objects/', '/context/', $item['thr-parent']);
 
 			if (isset($parent_item)) {
 				$conversation = DBA::selectFirst('conversation', ['conversation-uri', 'conversation-href'], ['item-uri' => $parent_item]);
diff --git a/src/Worker/OnePoll.php b/src/Worker/OnePoll.php
index 8f1e94580b..bdef1ac4d2 100644
--- a/src/Worker/OnePoll.php
+++ b/src/Worker/OnePoll.php
@@ -622,8 +622,8 @@ class OnePoll
 						}
 					}
 
-					if (empty($datarray['parent-uri'])) {
-						$datarray['parent-uri'] = $datarray['uri'];
+					if (!empty($datarray['parent-uri'])) {
+						$datarray['thr-parent'] = $datarray['parent-uri'];
 					}
 					unset($datarray['parent-uri']);
 
@@ -664,7 +664,7 @@ class OnePoll
 					$datarray['owner-link'] = "mailto:".$contact['addr'];
 					$datarray['owner-avatar'] = $contact['photo'];
 
-					if ($datarray['parent-uri'] === $datarray['uri']) {
+					if ($datarray['thr-parent'] === $datarray['uri']) {
 						$datarray['private'] = Item::PRIVATE;
 					}