diff --git a/src/app/api/portfolio/[portfolioId]/collaborators/route.test.ts b/src/app/api/portfolio/[portfolioId]/collaborators/inviteRequestSchema.test.ts
similarity index 94%
rename from src/app/api/portfolio/[portfolioId]/collaborators/route.test.ts
rename to src/app/api/portfolio/[portfolioId]/collaborators/inviteRequestSchema.test.ts
index 7b855f3f..e332c555 100644
--- a/src/app/api/portfolio/[portfolioId]/collaborators/route.test.ts
+++ b/src/app/api/portfolio/[portfolioId]/collaborators/inviteRequestSchema.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 
-import { inviteRequestSchema } from "./route";
+import { inviteRequestSchema } from "./inviteRequestSchema";
 
 describe("inviteRequestSchema", () => {
   it("accepts an invite request with just email and role (no name)", () => {
diff --git a/src/app/api/portfolio/[portfolioId]/collaborators/inviteRequestSchema.ts b/src/app/api/portfolio/[portfolioId]/collaborators/inviteRequestSchema.ts
new file mode 100644
index 00000000..12526c67
--- /dev/null
+++ b/src/app/api/portfolio/[portfolioId]/collaborators/inviteRequestSchema.ts
@@ -0,0 +1,10 @@
+import { z } from "zod";
+import { ROLE_OPTIONS } from "@/app/portfolio/[slug]/(portfolio)/settings/roles";
+
+// Body schema for POST /api/portfolio/[portfolioId]/collaborators. Lives in
+// its own file because Next.js 15 rejects non-handler named exports from
+// route.ts. See route.test.ts for the contract tests.
+export const inviteRequestSchema = z.object({
+  email: z.string().email(),
+  role: z.enum(ROLE_OPTIONS),
+});
diff --git a/src/app/api/portfolio/[portfolioId]/collaborators/route.ts b/src/app/api/portfolio/[portfolioId]/collaborators/route.ts
index 8fa8ca8d..4db4432b 100644
--- a/src/app/api/portfolio/[portfolioId]/collaborators/route.ts
+++ b/src/app/api/portfolio/[portfolioId]/collaborators/route.ts
@@ -29,6 +29,7 @@ import {
   denyIfNotAdmin,
   resolvePortfolioPrivilege,
 } from "@/app/lib/resolvePortfolioPrivilege";
+import { inviteRequestSchema } from "./inviteRequestSchema";
 
 // Get collaborators (users) that have access to the portfolio, plus the
 // effective privilege of the requesting user (so the UI knows which actions
@@ -192,13 +193,6 @@ export async function PUT(
   }
 }
 
-// Body schema for the invite endpoint. Exported so the contract can be
-// unit-tested directly — see route.test.ts.
-export const inviteRequestSchema = z.object({
-  email: z.string().email(),
-  role: z.enum(ROLE_OPTIONS),
-});
-
 // POST: invite a user by email.
 //
 // Unified flow: in nearly every case we write a pending portfolio_invitations