diff --git a/lib/Controller/ApiController.php b/lib/Controller/ApiController.php
index 61bca680..130dd6ba 100644
--- a/lib/Controller/ApiController.php
+++ b/lib/Controller/ApiController.php
@@ -78,7 +78,7 @@ public function createUser(int $providerId, string $userId, ?string $displayName
 	 */
 	public function deleteUser(string $userId): DataResponse {
 		$user = $this->userManager->get($userId);
-		if (is_null($user) || $user->getBackendClassName() !== 'user_oidc') {
+		if (is_null($user) || $user->getBackendClassName() !== Application::APP_ID) {
 			return new DataResponse(['message' => 'User not found'], Http::STATUS_NOT_FOUND);
 		}
 
diff --git a/lib/Controller/OcsApiController.php b/lib/Controller/OcsApiController.php
index dec92024..fbabc5ff 100644
--- a/lib/Controller/OcsApiController.php
+++ b/lib/Controller/OcsApiController.php
@@ -74,7 +74,7 @@ public function createUser(int $providerId, string $userId, ?string $displayName
 	 */
 	public function deleteUser(string $userId): DataResponse {
 		$user = $this->userManager->get($userId);
-		if (is_null($user) || $user->getBackendClassName() !== 'user_oidc') {
+		if (is_null($user) || $user->getBackendClassName() !== Application::APP_ID) {
 			return new DataResponse(['message' => 'User not found'], Http::STATUS_NOT_FOUND);
 		}
 
diff --git a/lib/Service/ProvisioningService.php b/lib/Service/ProvisioningService.php
index 02122a1d..39ba4db4 100644
--- a/lib/Service/ProvisioningService.php
+++ b/lib/Service/ProvisioningService.php
@@ -7,6 +7,7 @@
 
 namespace OCA\UserOIDC\Service;
 
+use OCA\UserOIDC\AppInfo\Application;
 use OCA\UserOIDC\Db\UserMapper;
 use OCA\UserOIDC\Event\AttributeMappedEvent;
 use OCP\Accounts\IAccountManager;
@@ -163,6 +164,12 @@ public function provisionUser(string $tokenUserId, int $providerId, object $idTo
 				$oldDisplayName = $user->getDisplayName();
 				if ($newDisplayName !== $oldDisplayName) {
 					$user->setDisplayName($newDisplayName);
+					if ($user->getBackendClassName() === Application::APP_ID) {
+						$backendUser = $this->userMapper->getOrCreate($providerId, $user->getUID());
+						$backendUser->setDisplayName($newDisplayName);
+						$this->userMapper->update($backendUser);
+					}
+					$this->eventDispatcher->dispatchTyped(new UserChangedEvent($user, 'displayName', $newDisplayName, $oldDisplayName));
 				}
 			}
 		}