diff --git a/prisma/seed.ts b/prisma/seed.ts
index d60eca4..95805e2 100644
--- a/prisma/seed.ts
+++ b/prisma/seed.ts
@@ -1,7 +1,12 @@
 import { PrismaClient, UserRole, RoomStatus } from '@prisma/client';
+import bcrypt from 'bcryptjs';
 
 const prisma = new PrismaClient();
 
+// Demo-Passwörter — nur für die Testdaten, sollten in Produktion geändert werden.
+const LANDLORD_DEMO_PASSWORD = 'Vermieter2026!';
+const TENANT_DEMO_PASSWORD = 'Mieter2026!';
+
 /**
  * Erzeugt Testdaten für die lokale Entwicklung:
  * - 1 Vermieter
@@ -11,6 +16,7 @@ const prisma = new PrismaClient();
  */
 async function main() {
   console.log('Seed: lösche vorhandene Testdaten...');
+  await prisma.invitation.deleteMany();
   await prisma.payment.deleteMany();
   await prisma.contract.deleteMany();
   await prisma.room.deleteMany();
@@ -19,7 +25,7 @@ async function main() {
   const landlord = await prisma.user.create({
     data: {
       email: 'vermieter@example.com',
-      passwordHash: 'not-a-real-hash',
+      passwordHash: await bcrypt.hash(LANDLORD_DEMO_PASSWORD, 12),
       fullName: 'Giuseppe Lombardo',
       role: UserRole.LANDLORD,
     },
@@ -49,7 +55,7 @@ async function main() {
     const tenant = await prisma.user.create({
       data: {
         email: `mieter${i + 1}@example.com`,
-        passwordHash: 'not-a-real-hash',
+        passwordHash: await bcrypt.hash(TENANT_DEMO_PASSWORD, 12),
         fullName: tenantNames[i],
         role: UserRole.TENANT,
         roomId: room.id,
@@ -79,7 +85,9 @@ async function main() {
     });
   }
 
-  console.log('Seed abgeschlossen. Vermieter-Login (Demo):', landlord.email);
+  console.log('Seed abgeschlossen.');
+  console.log(`Vermieter-Login (Demo): ${landlord.email} / ${LANDLORD_DEMO_PASSWORD}`);
+  console.log(`Mieter-Login (Demo, z.B. mieter1@example.com): ${TENANT_DEMO_PASSWORD}`);
 }
 
 main()