diff --git a/apps/user_ldap/lib/Migration/Version1010Date20200630192842.php b/apps/user_ldap/lib/Migration/Version1010Date20200630192842.php
index 939db69a6ab..5c7dc7db95c 100644
--- a/apps/user_ldap/lib/Migration/Version1010Date20200630192842.php
+++ b/apps/user_ldap/lib/Migration/Version1010Date20200630192842.php
@@ -47,7 +47,7 @@ class Version1010Date20200630192842 extends SimpleMigrationStep {
 			$table = $schema->createTable('ldap_user_mapping');
 			$table->addColumn('ldap_dn', Types::STRING, [
 				'notnull' => true,
-				'length' => 255,
+				'length' => 4000,
 				'default' => '',
 			]);
 			$table->addColumn('owncloud_name', Types::STRING, [
@@ -73,7 +73,7 @@ class Version1010Date20200630192842 extends SimpleMigrationStep {
 			$table = $schema->createTable('ldap_group_mapping');
 			$table->addColumn('ldap_dn', Types::STRING, [
 				'notnull' => true,
-				'length' => 255,
+				'length' => 4000,
 				'default' => '',
 			]);
 			$table->addColumn('owncloud_name', Types::STRING, [
diff --git a/apps/user_ldap/lib/Migration/Version1130Date20211102154716.php b/apps/user_ldap/lib/Migration/Version1130Date20211102154716.php
index 024c5801582..5c5ed44c899 100644
--- a/apps/user_ldap/lib/Migration/Version1130Date20211102154716.php
+++ b/apps/user_ldap/lib/Migration/Version1130Date20211102154716.php
@@ -95,8 +95,8 @@ class Version1130Date20211102154716 extends SimpleMigrationStep {
 			}
 			$column = $table->getColumn('ldap_dn');
 			if ($tableName === 'ldap_user_mapping') {
-				if ($column->getLength() < 4096) {
-					$column->setLength(4096);
+				if ($column->getLength() < 4000) {
+					$column->setLength(4000);
 					$changeSchema = true;
 				}
 
@@ -117,7 +117,7 @@ class Version1130Date20211102154716 extends SimpleMigrationStep {
 				$table2 = $schema->createTable('ldap_group_mapping_backup');
 				$table2->addColumn('ldap_dn', Types::STRING, [
 					'notnull' => true,
-					'length' => 4096,
+					'length' => 4000,
 					'default' => '',
 				]);
 				$table2->addColumn('owncloud_name', Types::STRING, [
diff --git a/apps/user_ldap/lib/Migration/Version1130Date20220110154718.php b/apps/user_ldap/lib/Migration/Version1130Date20220110154718.php
index 5f146ab06a5..74dd2d873bc 100644
--- a/apps/user_ldap/lib/Migration/Version1130Date20220110154718.php
+++ b/apps/user_ldap/lib/Migration/Version1130Date20220110154718.php
@@ -54,7 +54,7 @@ class Version1130Date20220110154718 extends GroupMappingMigration {
 		$table = $schema->createTable('ldap_group_mapping');
 		$table->addColumn('ldap_dn', Types::STRING, [
 			'notnull' => true,
-			'length' => 4096,
+			'length' => 4000,
 			'default' => '',
 		]);
 		$table->addColumn('owncloud_name', Types::STRING, [