diff --git a/src/core/server/app/middleware/passport/strategies/verifiers/sso.ts b/src/core/server/app/middleware/passport/strategies/verifiers/sso.ts
index 60c606b53..e48fdd1b7 100644
--- a/src/core/server/app/middleware/passport/strategies/verifiers/sso.ts
+++ b/src/core/server/app/middleware/passport/strategies/verifiers/sso.ts
@@ -64,7 +64,7 @@ export async function findOrCreateSSOUser(
   if (!user) {
     if (!integration.allowRegistration) {
       // Registration is disabled, so we can't create the user user here.
-      return;
+      return null;
     }
 
     // FIXME: (wyattjoh) implement rules! Not all users should be able to create an account via this method.