diff --git a/apps/files_sharing/lib/Repair/CleanupShareTarget.php b/apps/files_sharing/lib/Repair/CleanupShareTarget.php
index 340cc8840f04a..872fbb70930b0 100644
--- a/apps/files_sharing/lib/Repair/CleanupShareTarget.php
+++ b/apps/files_sharing/lib/Repair/CleanupShareTarget.php
@@ -118,16 +118,18 @@ public function run(IOutput $output) {
 					$oldMountPoint = "/{$recipient->getUID()}/files$oldTarget/";
 					$newMountPoint = "/{$recipient->getUID()}/files$newTarget/";
 
-					/** @var ICachedMountInfo $mount */
-					$mount = $userMounts[$oldMountPoint];
-					$userMounts[$newMountPoint] = $mount;
-					unset($userMounts[$oldMountPoint]);
-
-					$this->userMountCache->removeMount($oldMountPoint);
-					$this->userMountCache->addMount($recipient, $newMountPoint, new CacheEntry([
-						'fileid' => $mount->getRootId(),
-						'storage' => $mount->getStorageId(),
-					]), $mount->getMountProvider(), $mount->getMountId());
+					/** @var ICachedMountInfo|null $mount */
+					$mount = $userMounts[$oldMountPoint] ?? null;
+					if ($mount !== null) {
+						$userMounts[$newMountPoint] = $mount;
+						unset($userMounts[$oldMountPoint]);
+
+						$this->userMountCache->removeMount($oldMountPoint);
+						$this->userMountCache->addMount($recipient, $newMountPoint, new CacheEntry([
+							'fileid' => $mount->getRootId(),
+							'storage' => $mount->getStorageId(),
+						]), $mount->getMountProvider(), $mount->getMountId());
+					}
 				}
 			} catch (\Exception $e) {
 				$msg = 'error cleaning up share target: ' . $e->getMessage();
diff --git a/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php b/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php
index e781a8ec72ef2..ffc095196d36a 100644
--- a/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php
+++ b/apps/files_sharing/tests/Repair/CleanupShareTargetTest.php
@@ -10,6 +10,7 @@
 use OC\Migration\NullOutput;
 use OCA\Files_Sharing\Repair\CleanupShareTarget;
 use OCA\Files_Sharing\Tests\TestCase;
+use OCP\Files\Config\IUserMountCache;
 use OCP\Files\NotFoundException;
 use OCP\Server;
 use OCP\Share\IShare;
@@ -66,6 +67,17 @@ public function testBasicRepair() {
 		$this->assertEquals(self::TEST_FOLDER_NAME, $share->getTarget());
 	}
 
+	public function testRepairWithoutCachedMount() {
+		$share = $this->createUserShare(self::TEST_FILES_SHARING_API_USER1, self::TEST_FOLDER_NAME . ' (2) (2) (2) (2)');
+		$mountPoint = '/' . self::TEST_FILES_SHARING_API_USER2 . '/files' . $share->getTarget() . '/';
+		Server::get(IUserMountCache::class)->removeMount($mountPoint);
+
+		$this->cleanupShareTarget->run(new NullOutput());
+
+		$share = $this->shareManager->getShareById($share->getFullId());
+		$this->assertEquals(self::TEST_FOLDER_NAME, $share->getTarget());
+	}
+
 	public function testRepairConflictFile() {
 		$share = $this->createUserShare(self::TEST_FILES_SHARING_API_USER1, self::TEST_FOLDER_NAME . ' (2) (2) (2) (2)');