diff --git a/apps/files/lib/Service/OwnershipTransferService.php b/apps/files/lib/Service/OwnershipTransferService.php
index 581d5a1294801..5ee25e98ea8b6 100644
--- a/apps/files/lib/Service/OwnershipTransferService.php
+++ b/apps/files/lib/Service/OwnershipTransferService.php
@@ -17,6 +17,7 @@
 use OCA\Encryption\Util;
 use OCA\Files\Exception\TransferOwnershipException;
 use OCA\Files_External\Config\ConfigAdapter;
+use OCA\GroupFolders\Mount\GroupMountPoint;
 use OCP\Encryption\IManager as IEncryptionManager;
 use OCP\EventDispatcher\IEventDispatcher;
 use OCP\Files\Config\IHomeMountProvider;
@@ -169,6 +170,28 @@ public function transfer(
 		);
 		$sizeDifference = $sourceSize - $view->getFileInfo($finalTarget)->getSize();
 
+		// Files in Team folders are not transferred, so their size needs to be subtracted to avoid warnings about size differences
+		$mounts = Server::get(IMountManager::class)->getAll();
+		foreach ($mounts as $mount) {
+			if (!$mount instanceof GroupMountPoint || !str_starts_with($mount->getMountPoint(), '/' . $sourcePath . '/')) {
+				continue;
+			}
+
+			$storage = $mount->getStorage();
+			if ($storage === null) {
+				$output->writeln('Failed to get storage for mount: ' . $mount->getMountPoint());
+				continue;
+			}
+
+			$rootCacheEntry = $storage->getCache()->get('');
+			if ($rootCacheEntry === false) {
+				$output->writeln('Failed to get root cache entry for storage: ' . $mount->getMountPoint());
+				continue;
+			}
+
+			$sizeDifference -= $rootCacheEntry->getSize();
+		}
+
 		// transfer the incoming shares
 		$sourceShares = $this->collectIncomingShares(
 			$sourceUid,
diff --git a/psalm.xml b/psalm.xml
index 576c482532cd5..9b029ce31d497 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -114,6 +114,7 @@
 				<referencedClass name="OCA\TwoFactorNextcloudNotification\Controller\APIController"/>
 				<referencedClass name="OCA\GlobalSiteSelector\Service\SlaveService"/>
 				<referencedClass name="OCA\Guests\UserBackend"/>
+				<referencedClass name="OCA\GroupFolders\Mount\GroupMountPoint"/>
 			</errorLevel>
 		</UndefinedClass>
 		<UndefinedFunction>