diff --git a/backend/src/graphql/resolver/UserResolver.ts b/backend/src/graphql/resolver/UserResolver.ts
index 3b3ef394c..6d9e42405 100644
--- a/backend/src/graphql/resolver/UserResolver.ts
+++ b/backend/src/graphql/resolver/UserResolver.ts
@@ -306,7 +306,7 @@ export class UserResolver {
   @Authorized([RIGHTS.CREATE_USER])
   @Mutation(() => User)
   async createUser(
-    @Args() { email, firstName, lastName, language, publisherId, redeemCode }: CreateUserArgs,
+    @Args() { email, firstName, lastName, language, publisherId, redeemCode = null}: CreateUserArgs,
   ): Promise<User> {
     // TODO: wrong default value (should be null), how does graphql work here? Is it an required field?
     // default int publisher_id = 0;