diff --git a/apps/user_ldap/lib/Migration/Version1190Date20230706134108.php b/apps/user_ldap/lib/Migration/Version1190Date20230706134108.php
index 3f554f56e6436..71fdb536b1af3 100644
--- a/apps/user_ldap/lib/Migration/Version1190Date20230706134108.php
+++ b/apps/user_ldap/lib/Migration/Version1190Date20230706134108.php
@@ -99,13 +99,21 @@ protected function copyGroupMembershipData(): void {
 		$result = $query->executeQuery();
 		while ($row = $result->fetch()) {
 			$knownUsers = unserialize($row['owncloudusers']);
+			$knownUsers = array_unique($knownUsers);
 			foreach ($knownUsers as $knownUser) {
-				$insert
-					->setParameter('groupid', $row['owncloudname'])
-					->setParameter('userid', $knownUser)
-				;
+				try {
+					$insert
+						->setParameter('groupid', $row['owncloudname'])
+						->setParameter('userid', $knownUser)
+					;
 
-				$insert->executeStatement();
+					$insert->executeStatement();
+				} catch (\OCP\DB\Exception $e) {
+					/*
+					 * If it fails on unique constaint violation it may just be left over value from previous half-migration
+					 * If it fails on something else, ignore as well, data will be filled by background job later anyway
+					 */
+				}
 			}
 		}
 		$result->closeCursor();