diff --git a/app/api/listings/route.ts b/app/api/listings/route.ts
index feabad1..f00a41a 100644
--- a/app/api/listings/route.ts
+++ b/app/api/listings/route.ts
@@ -297,7 +297,7 @@ export async function POST(req: Request) {
         hasBarbecue: Boolean(body.hasBarbecue),
         evCharging: normalizeEvCharging(body.evCharging),
         priceHintPerNightEuros,
-        calendarUrls: calendarUrls.length ? calendarUrls : null,
+        calendarUrls,
         contactName,
         contactEmail,
         contactPhone: body.contactPhone ?? null,
diff --git a/prisma/migrations/20251127_calendar_urls/migration.sql b/prisma/migrations/20251127_calendar_urls/migration.sql
index 8746228..6f55b78 100644
--- a/prisma/migrations/20251127_calendar_urls/migration.sql
+++ b/prisma/migrations/20251127_calendar_urls/migration.sql
@@ -1,2 +1,2 @@
--- Add optional calendar URLs for availability sync (PostgreSQL text array)
-ALTER TABLE "Listing" ADD COLUMN "calendarUrls" TEXT[];
+-- Add calendar URLs for availability sync (PostgreSQL text array)
+ALTER TABLE "Listing" ADD COLUMN "calendarUrls" TEXT[] NOT NULL DEFAULT ARRAY[]::TEXT[];
diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index 2de4c38..4d1fd20 100644
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -93,7 +93,7 @@ model Listing {
   hasWashingMachine      Boolean             @default(false)
   hasBarbecue            Boolean             @default(false)
   evCharging             EvCharging          @default(NONE)
-  calendarUrls           String[]?           @db.Text[]
+  calendarUrls           String[]            @db.Text @default([])
   priceHintPerNightEuros Int?
   contactName            String
   contactEmail           String