diff --git a/database.sql b/database.sql
index 178c3fed6f..fcbcbb3941 100644
--- a/database.sql
+++ b/database.sql
@@ -715,7 +715,7 @@ CREATE TABLE IF NOT EXISTS `intro` (
 	`contact-id` int unsigned NOT NULL DEFAULT 0 COMMENT '',
 	`suggest-cid` int unsigned COMMENT 'Suggested contact',
 	`knowyou` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`duplex` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`duplex` boolean NOT NULL DEFAULT '0' COMMENT 'deprecated',
 	`note` text COMMENT '',
 	`hash` varchar(255) NOT NULL DEFAULT '' COMMENT '',
 	`datetime` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT '',
diff --git a/doc/database/db_intro.md b/doc/database/db_intro.md
index 0f2e36c705..3db6240d03 100644
--- a/doc/database/db_intro.md
+++ b/doc/database/db_intro.md
@@ -14,7 +14,7 @@ Fields
 | contact-id  |                   | int unsigned       | NO   |     | 0                   |                |
 | suggest-cid | Suggested contact | int unsigned       | YES  |     | NULL                |                |
 | knowyou     |                   | boolean            | NO   |     | 0                   |                |
-| duplex      |                   | boolean            | NO   |     | 0                   |                |
+| duplex      | deprecated        | boolean            | NO   |     | 0                   |                |
 | note        |                   | text               | YES  |     | NULL                |                |
 | hash        |                   | varchar(255)       | NO   |     |                     |                |
 | datetime    |                   | datetime           | NO   |     | 0001-01-01 00:00:00 |                |
diff --git a/src/Contact/Introduction/Depository/Introduction.php b/src/Contact/Introduction/Depository/Introduction.php
index b9752d8112..792673f23b 100644
--- a/src/Contact/Introduction/Depository/Introduction.php
+++ b/src/Contact/Introduction/Depository/Introduction.php
@@ -71,7 +71,6 @@ class Introduction extends BaseDepository
 			'contact-id'  => $introduction->cid,
 			'suggest-cid' => $introduction->sid,
 			'knowyou'     => $introduction->knowyou ? 1 : 0,
-			'duplex'      => $introduction->duplex ? 1 : 0,
 			'note'        => $introduction->note,
 			'hash'        => $introduction->hash,
 			'ignore'      => $introduction->ignore ? 1 : 0,
diff --git a/src/Contact/Introduction/Entity/Introduction.php b/src/Contact/Introduction/Entity/Introduction.php
index af9db729aa..9c5fb060ec 100644
--- a/src/Contact/Introduction/Entity/Introduction.php
+++ b/src/Contact/Introduction/Entity/Introduction.php
@@ -28,7 +28,6 @@ use Friendica\BaseEntity;
  * @property-read int $cid
  * @property-read int|null $sid
  * @property-read bool $knowyou
- * @property-read bool $duplex
  * @property-read string $note
  * @property-read string $hash
  * @property-read \DateTime $datetime
@@ -45,8 +44,6 @@ class Introduction extends BaseEntity
 	protected $sid;
 	/** @var bool */
 	protected $knowyou;
-	/** @var bool */
-	protected $duplex;
 	/** @var string */
 	protected $note;
 	/** @var string */
@@ -63,20 +60,18 @@ class Introduction extends BaseEntity
 	 * @param int       $cid
 	 * @param int|null  $sid
 	 * @param bool      $knowyou
-	 * @param bool      $duplex
 	 * @param string    $note
 	 * @param string    $hash
 	 * @param \DateTime $datetime
 	 * @param bool      $ignore
 	 * @param int|null  $id
 	 */
-	public function __construct(int $uid, int $cid, ?int $sid, bool $knowyou, bool $duplex, string $note, string $hash, \DateTime $datetime, bool $ignore, ?int $id)
+	public function __construct(int $uid, int $cid, ?int $sid, bool $knowyou, string $note, string $hash, \DateTime $datetime, bool $ignore, ?int $id)
 	{
 		$this->uid      = $uid;
 		$this->cid      = $cid;
 		$this->sid      = $sid;
 		$this->knowyou  = $knowyou;
-		$this->duplex   = $duplex;
 		$this->note     = $note;
 		$this->hash     = $hash;
 		$this->datetime = $datetime;
diff --git a/src/Contact/Introduction/Factory/Introduction.php b/src/Contact/Introduction/Factory/Introduction.php
index 57598f5e80..3bfa166b29 100644
--- a/src/Contact/Introduction/Factory/Introduction.php
+++ b/src/Contact/Introduction/Factory/Introduction.php
@@ -39,7 +39,6 @@ class Introduction extends BaseFactory implements ICanCreateFromTableRow
 			$row['contact-id'] ?? 0,
 			$row['suggest-cid'] ?? null,
 			!empty($row['knowyou']),
-			!empty($row['duplex']),
 			$row['note'] ?? '',
 			$row['hash'] ?? '',
 			new \DateTime($row['datetime'] ?? 'now', new \DateTimeZone('UTC')),
@@ -53,15 +52,13 @@ class Introduction extends BaseFactory implements ICanCreateFromTableRow
 		int $cid,
 		string $note,
 		int $sid = null,
-		bool $knowyou = false,
-		bool $duplex = false
+		bool $knowyou = false
 	): Entity\Introduction {
 		return $this->createFromTableRow([
 			'uid'         => $uid,
 			'suggest-cid' => $sid,
 			'contact-id'  => $cid,
 			'knowyou'     => $knowyou,
-			'duplex'      => $duplex,
 			'note'        => $note,
 			'hash'        => Strings::getRandomHex(),
 			'datetime'    => DateTimeFormat::utcNow(),
diff --git a/static/dbstructure.config.php b/static/dbstructure.config.php
index 4e478f0342..0019fdf7bf 100644
--- a/static/dbstructure.config.php
+++ b/static/dbstructure.config.php
@@ -778,7 +778,7 @@ return [
 			"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "foreign" => ["contact" => "id"], "comment" => ""],
 			"suggest-cid" => ["type" => "int unsigned", "foreign" => ["contact" => "id"], "comment" => "Suggested contact"],
 			"knowyou" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
-			"duplex" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+			"duplex" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "deprecated"],
 			"note" => ["type" => "text", "comment" => ""],
 			"hash" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
 			"datetime" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => ""],
diff --git a/tests/src/Contact/Introduction/Factory/IntroductionTest.php b/tests/src/Contact/Introduction/Factory/IntroductionTest.php
index 529d2720ef..e5efd03ddc 100644
--- a/tests/src/Contact/Introduction/Factory/IntroductionTest.php
+++ b/tests/src/Contact/Introduction/Factory/IntroductionTest.php
@@ -17,7 +17,6 @@ class IntroductionTest extends TestCase
 					'suggest-cid' => 13,
 					'contact-id'  => 24,
 					'knowyou'     => 1,
-					'duplex'      => 1,
 					'note'        => 'a note',
 					'hash'        => '12345',
 					'datetime'    => '1970-01-01 00:00:00',
@@ -29,7 +28,6 @@ class IntroductionTest extends TestCase
 					'suggest-cid' => 13,
 					'contact-id'  => 24,
 					'knowyou'     => true,
-					'duplex'      => true,
 					'note'        => 'a note',
 					'hash'        => '12345',
 					'datetime'    => new \DateTime('1970-01-01 00:00:00', new \DateTimeZone('UTC')),
@@ -45,7 +43,6 @@ class IntroductionTest extends TestCase
 					'contact-id'  => 0,
 					'suggest-cid' => null,
 					'knowyou'     => false,
-					'duplex'      => false,
 					'note'        => '',
 					'ignore'      => false,
 					'id'          => null,
@@ -61,7 +58,6 @@ class IntroductionTest extends TestCase
 		self::assertEquals($intro->cid, $assertion['contact-id'] ?? 0);
 		self::assertEquals($intro->sid, $assertion['suggest-cid'] ?? null);
 		self::assertEquals($intro->knowyou, $assertion['knowyou'] ?? false);
-		self::assertEquals($intro->duplex, $assertion['duplex'] ?? false);
 		self::assertEquals($intro->note, $assertion['note'] ?? '');
 		if (isset($assertion['hash'])) {
 			self::assertEquals($intro->hash, $assertion['hash']);