diff --git a/database.sql b/database.sql
index 520c5e9b05..99053884d8 100644
--- a/database.sql
+++ b/database.sql
@@ -470,7 +470,7 @@ CREATE TABLE IF NOT EXISTS `delayed-post` (
 	`uid` mediumint unsigned COMMENT 'Owner User id',
 	`delayed` datetime COMMENT 'delay time',
 	 PRIMARY KEY(`id`),
-	 UNIQUE INDEX `uri` (`uri`(190)),
+	 UNIQUE INDEX `uid_uri` (`uid`,`uri`(190)),
 	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Posts that are about to be posted at a later time';
 
diff --git a/src/Model/Post/Delayed.php b/src/Model/Post/Delayed.php
index 963122b5b8..a29d05422a 100644
--- a/src/Model/Post/Delayed.php
+++ b/src/Model/Post/Delayed.php
@@ -42,7 +42,7 @@ class Delayed
 	 */ 
 	public static function add(string $delayed, array $item, int $notify = 0, array $taglist = [], array $attachments = [])
 	{
-		if (empty($item['uri']) || empty($item['uid']) || self::exists($item['uri'])) {
+		if (empty($item['uri']) || empty($item['uid']) || self::exists($item['uri'], $item['uid'])) {
 			return false;
 		}
 
@@ -59,9 +59,9 @@ class Delayed
 	 *
 	 * @return bool delete success
 	 */
-	private static function delete(string $uri)
+	private static function delete(string $uri, int $uid)
 	{
-		return DBA::delete('delayed-post', ['uri' => $uri]);
+		return DBA::delete('delayed-post', ['uri' => $uri, 'uid' => $uid]);
 	}
 
 	/**
@@ -71,9 +71,9 @@ class Delayed
 	 *
 	 * @return bool "true" if an entry with that URI exists
 	 */
-	public static function exists(string $uri)
+	public static function exists(string $uri, int $uid)
 	{
-		return DBA::exists('delayed-post', ['uri' => $uri]);
+		return DBA::exists('delayed-post', ['uri' => $uri, 'uid' => $uid]);
 	}
 
 	/**
@@ -93,7 +93,7 @@ class Delayed
 
 		// It should always contain an URI since this is needed to create a delayed post entry
 		if (!empty($item['uri'])) {
-			$result = self::delete($item['uri']);
+			$result = self::delete($item['uri'], $item['uid']);
 			Logger::notice('Delayed post entry deleted', ['result' => $result, 'uri' => $item['uri']]);
 		}
 
diff --git a/src/Protocol/Feed.php b/src/Protocol/Feed.php
index 48677a91b7..ed24defc2e 100644
--- a/src/Protocol/Feed.php
+++ b/src/Protocol/Feed.php
@@ -615,7 +615,7 @@ class Feed
 			}
 
 			$condition = ['uid' => $item['uid'], 'uri' => $item['uri']];
-			if (!Item::exists($condition) && !Post\Delayed::exists($item["uri"])) {
+			if (!Item::exists($condition) && !Post\Delayed::exists($item["uri"], $item['uid'])) {
 				$postings[] = ['item' => $item, 'notify' => $notify,
 					'taglist' => $taglist, 'attachments' => $attachments];
 			} else {
diff --git a/static/dbstructure.config.php b/static/dbstructure.config.php
index 9af9c46257..106ae4e3f0 100644
--- a/static/dbstructure.config.php
+++ b/static/dbstructure.config.php
@@ -537,7 +537,7 @@ return [
 		],
 		"indexes" => [
 			"PRIMARY" => ["id"],
-			"uri" => ["UNIQUE", "uri(190)"],
+			"uid_uri" => ["UNIQUE", "uid", "uri(190)"],
 		]
 	],
 	"diaspora-interaction" => [