diff --git a/lib/Controller/LoginController.php b/lib/Controller/LoginController.php
index 0ae3b997..b66a5137 100644
--- a/lib/Controller/LoginController.php
+++ b/lib/Controller/LoginController.php
@@ -464,6 +464,7 @@ private function provisionUser(string $userId, int $providerId, object $idTokenP
 			// so new users will be directly available even if they were not synced before this login attempt
 			$this->userManager->search($userId);
 			// when auto provision is disabled, we assume the user has been created by another user backend (or manually)
+			$userId = $this->ldapService->mapLoginName2UserName($userId);
 			$user = $this->userManager->get($userId);
 			if (is_null($user) || $this->ldapService->isLdapDeletedUser($user)) {
 				$this->logger->warning("Won't provision user: " . $userId);
diff --git a/lib/Service/LdapService.php b/lib/Service/LdapService.php
index 4642cd50..cd928a7a 100644
--- a/lib/Service/LdapService.php
+++ b/lib/Service/LdapService.php
@@ -72,4 +72,22 @@ public function isLdapDeletedUser(IUser $user): bool {
 		// did we find the user in the LDAP deleted user list?
 		return $searchDisabledUser !== false;
 	}
+
+	/**
+	 * @param string $userId
+	 * @return string
+	 */
+	public function mapLoginName2UserName(string $userId): string {
+		try {
+			$proxy = \OC::$server->get(\OCA\User_LDAP\User_Proxy::class);
+			$mappedUserId = $proxy->loginName2UserName($userId);
+			if ($mappedUserId !== false && $mappedUserId !== $userId) {
+				$userId = $mappedUserId;
+			}
+		} catch (QueryException $e) {
+			$this->logger->debug($e->getMessage());
+		} finally {
+			return $userId;
+		}
+	}
 }