diff --git a/app/layout.tsx b/app/layout.tsx
index b09f9e7..224a250 100644
--- a/app/layout.tsx
+++ b/app/layout.tsx
@@ -24,7 +24,7 @@ export const metadata: Metadata = {
   },
   description:
     "PodcastYes is an all-in-one AI platform that writes your script, records realistic multi-voice audio, and designs cover art — turning a topic into a finished episode in minutes.",
-  metadataBase: new URL(process.env.NEXT_PUBLIC_APP_URL ?? "http://localhost:3000"),
+  metadataBase: new URL(process.env.NEXT_PUBLIC_APP_URL || "http://localhost:3000"),
   openGraph: {
     title: "PodcastYes",
     description: "Create scripted, narrated, illustrated podcasts with AI — no recording gear required.",
diff --git a/lib/ai/pipeline/generate-episode.ts b/lib/ai/pipeline/generate-episode.ts
index b84f136..da11760 100644
--- a/lib/ai/pipeline/generate-episode.ts
+++ b/lib/ai/pipeline/generate-episode.ts
@@ -261,7 +261,7 @@ async function generateArt(episode: EpisodeWithRelations) {
 }
 
 async function notifyReady(episode: EpisodeWithRelations) {
-  const appUrl = process.env.NEXT_PUBLIC_APP_URL ?? "http://localhost:3000";
+  const appUrl = process.env.NEXT_PUBLIC_APP_URL || "http://localhost:3000";
   try {
     await sendEmail({
       to: episode.user.email,
diff --git a/lib/auth/auth-client.ts b/lib/auth/auth-client.ts
index 8713375..f408cb0 100644
--- a/lib/auth/auth-client.ts
+++ b/lib/auth/auth-client.ts
@@ -4,7 +4,7 @@ import { createAuthClient } from "better-auth/react";
 import { adminClient, organizationClient } from "better-auth/client/plugins";
 
 export const authClient = createAuthClient({
-  baseURL: process.env.NEXT_PUBLIC_APP_URL ?? undefined,
+  baseURL: process.env.NEXT_PUBLIC_APP_URL || undefined,
   plugins: [adminClient(), organizationClient()],
 });
 
diff --git a/lib/auth/auth.ts b/lib/auth/auth.ts
index 061c64e..5dda84e 100644
--- a/lib/auth/auth.ts
+++ b/lib/auth/auth.ts
@@ -5,7 +5,7 @@ import { nextCookies } from "better-auth/next-js";
 import { prisma } from "@/lib/db";
 import { sendEmail, emailLayout } from "@/lib/email";
 
-const appUrl = process.env.NEXT_PUBLIC_APP_URL ?? "http://localhost:3000";
+const appUrl = process.env.NEXT_PUBLIC_APP_URL || "http://localhost:3000";
 
 const googleConfigured = !!(process.env.GOOGLE_CLIENT_ID && process.env.GOOGLE_CLIENT_SECRET);
 
diff --git a/lib/billing/paypal.ts b/lib/billing/paypal.ts
index 8aa086b..1270b51 100644
--- a/lib/billing/paypal.ts
+++ b/lib/billing/paypal.ts
@@ -2,7 +2,7 @@ import type { PlanKey } from "./plans";
 
 const SANDBOX_BASE = "https://api-m.sandbox.paypal.com";
 const base = () => process.env.PAYPAL_API_BASE ?? SANDBOX_BASE;
-const appUrl = () => process.env.NEXT_PUBLIC_APP_URL ?? "http://localhost:3000";
+const appUrl = () => process.env.NEXT_PUBLIC_APP_URL || "http://localhost:3000";
 
 // Loudly warn (but don't throw — never break deploys) if PayPal is pointed at the
 // sandbox while running in production. The sandbox default is fine for dev.
diff --git a/lib/billing/stripe.ts b/lib/billing/stripe.ts
index f9f2cd6..c6c8292 100644
--- a/lib/billing/stripe.ts
+++ b/lib/billing/stripe.ts
@@ -18,7 +18,7 @@ export function isStripeConfigured(): boolean {
   return !!process.env.STRIPE_SECRET_KEY;
 }
 
-const appUrl = () => process.env.NEXT_PUBLIC_APP_URL ?? "http://localhost:3000";
+const appUrl = () => process.env.NEXT_PUBLIC_APP_URL || "http://localhost:3000";
 
 /** Find-or-create the Stripe customer for a user and persist the id. */
 export async function ensureStripeCustomer(user: {