diff --git a/apps/federatedfilesharing/appinfo/Migrations/Version20190410160725.php b/apps/federatedfilesharing/appinfo/Migrations/Version20190410160725.php
new file mode 100644
index 000000000000..e3423044fb57
--- /dev/null
+++ b/apps/federatedfilesharing/appinfo/Migrations/Version20190410160725.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace OCA\FederatedFileSharing\Migrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\DBAL\Types\Type;
+use OCP\Migration\ISchemaMigration;
+
+/** Updates remote_id to be string if required */
+class Version20190410160725 implements ISchemaMigration {
+	public function changeSchema(Schema $schema, array $options) {
+		$prefix = $options['tablePrefix'];
+
+		if ($schema->hasTable("${prefix}federated_reshares")) {
+			$table = $schema->getTable("{$prefix}federated_reshares");
+			$remoteIdColumn = $table->getColumn('remote_id');
+			if ($remoteIdColumn && $remoteIdColumn->getType()->getName() !== Type::STRING) {
+				$remoteIdColumn->setType(Type::getType(Type::STRING));
+				$remoteIdColumn->setOptions(['length' => 255]);
+			}
+		}
+
+		if ($schema->hasTable("${prefix}share_external")) {
+			$table = $schema->getTable("{$prefix}share_external");
+			$remoteIdColumn = $table->getColumn('remote_id');
+			if ($remoteIdColumn && $remoteIdColumn->getType()->getName() !== Type::STRING) {
+				$remoteIdColumn->setType(Type::getType(Type::STRING));
+				$remoteIdColumn->setOptions(['length' => 255]);
+			}
+		}
+	}
+}
diff --git a/apps/federatedfilesharing/appinfo/info.xml b/apps/federatedfilesharing/appinfo/info.xml
index 83be1d798644..45ccca83c4f5 100644
--- a/apps/federatedfilesharing/appinfo/info.xml
+++ b/apps/federatedfilesharing/appinfo/info.xml
@@ -5,7 +5,7 @@
     <description>Provide federated file sharing across ownCloud servers</description>
     <licence>AGPL</licence>
     <author>Bjoern Schiessle, Roeland Jago Douma</author>
-    <version>0.4.0</version>
+    <version>0.5.0</version>
     <namespace>FederatedFileSharing</namespace>
     <use-migrations>true</use-migrations>
     <category>other</category>
diff --git a/apps/federatedfilesharing/lib/FedShareManager.php b/apps/federatedfilesharing/lib/FedShareManager.php
index c7c7d99513d3..7f904854598f 100644
--- a/apps/federatedfilesharing/lib/FedShareManager.php
+++ b/apps/federatedfilesharing/lib/FedShareManager.php
@@ -116,7 +116,7 @@ public function __construct(FederatedShareProvider $federatedShareProvider,
 	 * @param Address $ownerAddress
 	 * @param Address $sharedByAddress
 	 * @param string $shareWith
-	 * @param int $remoteId
+	 * @param string $remoteId
 	 * @param string $name
 	 * @param string $token
 	 *
@@ -181,7 +181,7 @@ public function createShare(Address $ownerAddress,
 
 	/**
 	 * @param IShare $share
-	 * @param int $remoteId
+	 * @param string $remoteId
 	 * @param string $shareWith
 	 * @param int|null $permissions - null for OCM 1.0-proposal1
 	 *
diff --git a/apps/federatedfilesharing/lib/FederatedShareProvider.php b/apps/federatedfilesharing/lib/FederatedShareProvider.php
index 70393a2e0190..f80fa3b1efbf 100644
--- a/apps/federatedfilesharing/lib/FederatedShareProvider.php
+++ b/apps/federatedfilesharing/lib/FederatedShareProvider.php
@@ -302,7 +302,7 @@ protected function getShareFromExternalShareTable(IShare $share) {
 			->andWhere($query->expr()->eq('mountpoint', $query->createNamedParameter($share->getTarget())));
 		$result = $query->execute()->fetchAll();
 
-		if (isset($result[0]) && (int)$result[0]['remote_id'] > 0) {
+		if (isset($result[0]) && $result[0]['remote_id'] !== "") {
 			return $result[0];
 		}
 
@@ -427,7 +427,7 @@ public function storeRemoteId($shareId, $remoteId) {
 	 * get share ID on remote server for federated re-shares
 	 *
 	 * @param IShare $share
-	 * @return int
+	 * @return string
 	 * @throws ShareNotFound
 	 */
 	public function getRemoteId(IShare $share) {
@@ -440,7 +440,7 @@ public function getRemoteId(IShare $share) {
 			throw new ShareNotFound();
 		}
 
-		return (int)$data['remote_id'];
+		return $data['remote_id'];
 	}
 
 	/**
@@ -975,7 +975,7 @@ public function updateForRecipient(IShare $share, $recipient) {
 	}
 
 	/**
-	 * @param int $remoteId
+	 * @param string $remoteId
 	 * @param string $shareToken
 	 * @return mixed
 	 */
diff --git a/apps/federatedfilesharing/lib/Notifications.php b/apps/federatedfilesharing/lib/Notifications.php
index 3a1bc0e64ead..92df22ccdd75 100644
--- a/apps/federatedfilesharing/lib/Notifications.php
+++ b/apps/federatedfilesharing/lib/Notifications.php
@@ -83,7 +83,7 @@ public function __construct(
 	 * @param Address $sharedByAddress
 	 * @param string $token
 	 * @param string $name
-	 * @param int $remote_id
+	 * @param string $remote_id
 	 *
 	 * @return bool
 	 *
@@ -148,7 +148,7 @@ public function requestReShare($token, $id, $shareId, $remote, $shareWith, $perm
 			if (\is_array($response) && isset($response['sharedSecret'], $response['providerId'])) {
 				return [
 					$response['sharedSecret'],
-					(int) $response['providerId']
+					$response['providerId']
 				];
 			}
 			return true;
@@ -172,7 +172,7 @@ public function requestReShare($token, $id, $shareId, $remote, $shareWith, $perm
 		if ($httpRequestSuccessful && $this->isOcsStatusOk($status) && $validToken && $validRemoteId) {
 			return [
 				$status['ocs']['data']['token'],
-				(int)$status['ocs']['data']['remoteId']
+				$status['ocs']['data']['remoteId']
 			];
 		}
 
@@ -207,7 +207,7 @@ public function sendRevokeShare($remote, $id, $token) {
 	 * send notification to remote server if the permissions was changed
 	 *
 	 * @param string $remote
-	 * @param int $remoteId
+	 * @param string $remoteId
 	 * @param string $token
 	 * @param int $permissions
 	 * @return bool
@@ -220,7 +220,7 @@ public function sendPermissionChange($remote, $remoteId, $token, $permissions) {
 	 * forward accept reShare to remote server
 	 *
 	 * @param string $remote
-	 * @param int $remoteId
+	 * @param string $remoteId
 	 * @param string $token
 	 */
 	public function sendAcceptShare($remote, $remoteId, $token) {
@@ -231,7 +231,7 @@ public function sendAcceptShare($remote, $remoteId, $token) {
 	 * forward decline reShare to remote server
 	 *
 	 * @param string $remote
-	 * @param int $remoteId
+	 * @param string $remoteId
 	 * @param string $token
 	 */
 	public function sendDeclineShare($remote, $remoteId, $token) {
@@ -242,7 +242,7 @@ public function sendDeclineShare($remote, $remoteId, $token) {
 	 * inform remote server whether server-to-server share was accepted/declined
 	 *
 	 * @param string $remote
-	 * @param int $remoteId Share id on the remote host
+	 * @param string $remoteId Share id on the remote host
 	 * @param string $token
 	 * @param string $action possible actions:
 	 * 	                     accept, decline, unshare, revoke, permissions
@@ -371,7 +371,7 @@ protected function sendOcmRemoteShare(Address $shareWithAddress, Address $ownerA
 		$fields = [
 			'shareWith' => $shareWithAddress->getCloudId(),
 			'name' => $name,
-			'providerId' => $remote_id,
+			'providerId' => (string) $remote_id,
 			'owner' => $ownerAddress->getCloudId(),
 			'ownerDisplayName' => $ownerAddress->getDisplayName(),
 			'sender' => $sharedByAddress->getCloudId(),
diff --git a/apps/federatedfilesharing/tests/FederatedShareProviderTest.php b/apps/federatedfilesharing/tests/FederatedShareProviderTest.php
index ee0a66eef616..e805b9afaa83 100644
--- a/apps/federatedfilesharing/tests/FederatedShareProviderTest.php
+++ b/apps/federatedfilesharing/tests/FederatedShareProviderTest.php
@@ -24,11 +24,14 @@
  */
 namespace OCA\FederatedFileSharing\Tests;
 
+use Doctrine\DBAL\Driver\Statement;
 use OCA\FederatedFileSharing\Address;
 use OCA\FederatedFileSharing\AddressHandler;
 use OCA\FederatedFileSharing\FederatedShareProvider;
 use OCA\FederatedFileSharing\Notifications;
 use OCA\FederatedFileSharing\TokenHandler;
+use OCP\DB\QueryBuilder\IExpressionBuilder;
+use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\Files\IRootFolder;
 use OCP\IConfig;
 use OCP\IDBConnection;
@@ -945,4 +948,38 @@ public function dataTestGetAccepted() {
 			[false, 'yes', 'yes', true, true],
 		];
 	}
+
+	public function testGetRemoteId() {
+		$exprBuilder = $this->createMock(IExpressionBuilder::class);
+		$statementMock = $this->createMock(Statement::class);
+		$statementMock->method('fetch')->willReturn(['remote_id' => 'a0b0c0']);
+
+		$qbMock = $this->createMock(IQueryBuilder::class);
+		$qbMock->method('select')->willReturnSelf();
+		$qbMock->method('from')->willReturnSelf();
+		$qbMock->method('where')->willReturnSelf();
+		$qbMock->method('expr')->willReturn($exprBuilder);
+		$qbMock->method('execute')->willReturn($statementMock);
+		$connectionMock = $this->createMock(IDBConnection::class);
+		$connectionMock->method('getQueryBuilder')->willReturn($qbMock);
+
+		$shareMock = $this->createMock(IShare::class);
+		$this->provider = new FederatedShareProvider(
+			$connectionMock,
+			$this->eventDispatcher,
+			$this->addressHandler,
+			$this->notifications,
+			$this->tokenHandler,
+			$this->l,
+			$this->logger,
+			$this->rootFolder,
+			$this->config,
+			$this->userManager
+		);
+
+		$this->assertEquals(
+			'a0b0c0',
+			$this->provider->getRemoteId($shareMock)
+		);
+	}
 }
diff --git a/apps/federatedfilesharing/tests/appinfo/Migrations/Version20190410160725Test.php b/apps/federatedfilesharing/tests/appinfo/Migrations/Version20190410160725Test.php
new file mode 100644
index 000000000000..871d4fd9c401
--- /dev/null
+++ b/apps/federatedfilesharing/tests/appinfo/Migrations/Version20190410160725Test.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace OCA\FederatedFileSharing\Tests\appinfo\Migrations;
+
+// FIXME: autoloader fails to load migration
+require_once \dirname(\dirname(\dirname(__DIR__))) . "/appinfo/Migrations/Version20190410160725.php";
+
+use Doctrine\DBAL\Schema\Table;
+use OCA\FederatedFileSharing\Migrations\Version20190410160725;
+use Test\TestCase;
+use Doctrine\DBAL\Schema\Schema;
+
+class Version20190410160725Test extends TestCase {
+	public function testExecute() {
+		$tablePrefix = 'pr_';
+		$migration = new Version20190410160725();
+		$table = $this->createMock(Table::class);
+		$schema = $this->createMock(Schema::class);
+		$schema->method('hasTable')->withConsecutive(
+			['pr_federated_reshares'],
+			['pr_share_external']
+		)->willReturn(true);
+		$schema->method('getTable')->withConsecutive(
+			['pr_federated_reshares'],
+			['pr_share_external']
+		)->willReturn($table);
+
+		$this->assertNull($migration->changeSchema($schema, ['tablePrefix' => $tablePrefix]));
+	}
+}
diff --git a/apps/files_sharing/lib/External/Manager.php b/apps/files_sharing/lib/External/Manager.php
index 4a411cad15d8..105cebc7a32a 100644
--- a/apps/files_sharing/lib/External/Manager.php
+++ b/apps/files_sharing/lib/External/Manager.php
@@ -103,7 +103,7 @@ public function __construct(\OCP\IDBConnection $connection,
 	 * @param string $owner
 	 * @param boolean $accepted
 	 * @param string $user
-	 * @param int $remoteId
+	 * @param string $remoteId
 	 * @return Mount|null
 	 */
 	public function addShare($remote, $token, $password, $name, $owner, $accepted=false, $user = null, $remoteId = -1) {
diff --git a/lib/public/Share/Events/ShareEvent.php b/lib/public/Share/Events/ShareEvent.php
index 34182b9b826f..a06836594b59 100644
--- a/lib/public/Share/Events/ShareEvent.php
+++ b/lib/public/Share/Events/ShareEvent.php
@@ -62,11 +62,11 @@ public function getRemote() {
 	}
 
 	/**
-	 * @return int
+	 * @return string
 	 * @since 10.0.2
 	 */
 	public function getRemoteId() {
-		return (int)$this->share['remote_id'];
+		return $this->share['remote_id'];
 	}
 
 	/**