diff --git a/apps/files_versions/lib/Controller/PreviewController.php b/apps/files_versions/lib/Controller/PreviewController.php
index f41250a89710fcf48bcac38e683126abd4288228..28d16b8a96b0831f858a678021b0c3d136acefe1 100644
--- a/apps/files_versions/lib/Controller/PreviewController.php
+++ b/apps/files_versions/lib/Controller/PreviewController.php
@@ -95,7 +95,7 @@ class PreviewController extends Controller {
 			$user = $this->userSession->getUser();
 			$userFolder = $this->rootFolder->getUserFolder($user->getUID());
 			$file = $userFolder->get($file);
-			$versionFile = $this->versionManager->getVersionFile($user, $file, (int)$version);
+			$versionFile = $this->versionManager->getVersionFile($user, $file, $version);
 			$preview = $this->previewManager->getPreview($versionFile, $x, $y, true, IPreview::MODE_FILL, $versionFile->getMimetype());
 			return new FileDisplayResponse($preview, Http::STATUS_OK, ['Content-Type' => $preview->getMimeType()]);
 		} catch (NotFoundException $e) {
diff --git a/apps/files_versions/lib/Versions/IVersion.php b/apps/files_versions/lib/Versions/IVersion.php
index b6fc95814d84b9c32ba20066d909b5e82592dd0b..d12bdc9d0ba0240eba64c512857e71284e63d31e 100644
--- a/apps/files_versions/lib/Versions/IVersion.php
+++ b/apps/files_versions/lib/Versions/IVersion.php
@@ -46,10 +46,10 @@ interface IVersion {
 	/**
 	 * Get the id of the revision for the file
 	 *
-	 * @return int
+	 * @return int|string
 	 * @since 15.0.0
 	 */
-	public function getRevisionId(): int;
+	public function getRevisionId();
 
 	/**
 	 * Get the timestamp this version was created
diff --git a/apps/files_versions/lib/Versions/IVersionBackend.php b/apps/files_versions/lib/Versions/IVersionBackend.php
index 913745c9850b329a8f591b366f8c8bfb0f3bb094..055d2eab174cb031f350aac2fcaa7ba88ae7f2f1 100644
--- a/apps/files_versions/lib/Versions/IVersionBackend.php
+++ b/apps/files_versions/lib/Versions/IVersionBackend.php
@@ -85,9 +85,9 @@ interface IVersionBackend {
 	 *
 	 * @param IUser $user
 	 * @param FileInfo $sourceFile
-	 * @param int $revision
+	 * @param int|string $revision
 	 * @return ISimpleFile
 	 * @since 15.0.0
 	 */
-	public function getVersionFile(IUser $user, FileInfo $sourceFile, int $revision): File;
+	public function getVersionFile(IUser $user, FileInfo $sourceFile, $revision): File;
 }
diff --git a/apps/files_versions/lib/Versions/LegacyVersionsBackend.php b/apps/files_versions/lib/Versions/LegacyVersionsBackend.php
index aceddef29d29e09daf6ef17612c3d1e3a4d37723..46bd2ea8d467f00bf10cbe0dc3dd1ae0b41e4058 100644
--- a/apps/files_versions/lib/Versions/LegacyVersionsBackend.php
+++ b/apps/files_versions/lib/Versions/LegacyVersionsBackend.php
@@ -113,7 +113,7 @@ class LegacyVersionsBackend implements IVersionBackend {
 		return $file->fopen('r');
 	}
 
-	public function getVersionFile(IUser $user, FileInfo $sourceFile, int $revision): File {
+	public function getVersionFile(IUser $user, FileInfo $sourceFile, $revision): File {
 		$userFolder = $this->rootFolder->getUserFolder($user->getUID());
 		$versionFolder = $this->getVersionFolder($user);
 		/** @var File $file */
diff --git a/apps/files_versions/lib/Versions/Version.php b/apps/files_versions/lib/Versions/Version.php
index 5988234db6140495e2b71ca17864fc291c37217c..3a60dc0731c6093cff247d87e068fa29c6f9a698 100644
--- a/apps/files_versions/lib/Versions/Version.php
+++ b/apps/files_versions/lib/Versions/Version.php
@@ -29,7 +29,7 @@ class Version implements IVersion {
 	/** @var int */
 	private $timestamp;
 
-	/** @var int */
+	/** @var int|string */
 	private $revisionId;
 
 	/** @var string */
@@ -55,7 +55,7 @@ class Version implements IVersion {
 
 	public function __construct(
 		int $timestamp,
-		int $revisionId,
+		$revisionId,
 		string $name,
 		int $size,
 		string $mimetype,
@@ -83,7 +83,7 @@ class Version implements IVersion {
 		return $this->sourceFileInfo;
 	}
 
-	public function getRevisionId(): int {
+	public function getRevisionId() {
 		return $this->revisionId;
 	}
 
diff --git a/apps/files_versions/lib/Versions/VersionManager.php b/apps/files_versions/lib/Versions/VersionManager.php
index 99fa9f62bc853746601feec314795ec50ad14ba1..23cf43ba357a0ee4439aaedfcc68909a2fb93716 100644
--- a/apps/files_versions/lib/Versions/VersionManager.php
+++ b/apps/files_versions/lib/Versions/VersionManager.php
@@ -98,7 +98,7 @@ class VersionManager implements IVersionManager {
 		return $backend->read($version);
 	}
 
-	public function getVersionFile(IUser $user, FileInfo $sourceFile, int $revision): File {
+	public function getVersionFile(IUser $user, FileInfo $sourceFile, $revision): File {
 		$backend = $this->getBackendForStorage($sourceFile->getStorage());
 		return $backend->getVersionFile($user, $sourceFile, $revision);
 	}