diff --git a/controller/links.ts b/controller/links.ts
index 36372a1..8a7aff6 100644
--- a/controller/links.ts
+++ b/controller/links.ts
@@ -18,14 +18,14 @@ export const getLinkObjectById = (shortenedId: string) => ShortenedLink.findOne(
  * @param shortenedId The custom id of the link (optional)
  * @param clientId The client id of the user that created the link
  */
-export const shortLink = (originalUrl: string, shortenedId: string | undefined, clientId: number) =>
+export const shortLink = (originalUrl: string, shortenedId: string | undefined, clientId: string) =>
     ShortenedLink.create({originalUrl, shortenedId, clientId});
 
 /**
  * Lists all links created by a specific user
  * @param clientId The user to get the links from
  */
-export const listLinksByUser = (clientId: number) => ShortenedLink.findAll({where: {clientId}});
+export const listLinksByUser = (clientId: string) => ShortenedLink.findAll({where: {clientId}});
 
 /** Lists all created links from the database */
 export const listAllLinks = () => ShortenedLink.findAll({});
\ No newline at end of file
diff --git a/controller/media.ts b/controller/media.ts
index d14de7d..8622afc 100644
--- a/controller/media.ts
+++ b/controller/media.ts
@@ -8,7 +8,7 @@ import {bucket} from "./bucket";
  * @param assetName The name of the asset
  * @param assetEnding The file ending of the asset
  */
-export const createMedia = (clientId: number, assetName: string, assetEnding: string | undefined) =>
+export const createMedia = (clientId: string, assetName: string, assetEnding: string | undefined) =>
     Media.create({clientId, assetName, assetEnding: assetEnding || "txt"});
 
 /**