diff --git a/.env.sample b/.env.sample
index 3bd68d8e4..51d02bf37 100644
--- a/.env.sample
+++ b/.env.sample
@@ -18,6 +18,7 @@ FCC_ENABLE_DEV_LOGIN_MODE=true
 
 # Student progress data. The mock server (pnpm run mock-fcc-data) is the default.
 # Set FCC_API_URL and TPA_API_BEARER_TOKEN to use the freeCodeCamp API instead.
+# Production requires FCC_API_URL.
 MOCK_USER_DATA_URL=http://localhost:3002/data
 FCC_API_URL=
 TPA_API_BEARER_TOKEN=
diff --git a/__tests__/utils/env.test.ts b/__tests__/utils/env.test.ts
index 189738c20..cd228b877 100644
--- a/__tests__/utils/env.test.ts
+++ b/__tests__/utils/env.test.ts
@@ -15,7 +15,9 @@ const productionEnv: NodeJS.ProcessEnv = {
   NEXTAUTH_SECRET: 'test-production-secret',
   AUTH0_DOMAIN: 'example.auth0.com',
   AUTH0_CLIENT_ID: 'test-client-id',
-  AUTH0_CLIENT_SECRET: 'test-client-secret'
+  AUTH0_CLIENT_SECRET: 'test-client-secret',
+  // TODO: replace with the real freeCodeCamp API URL once it is confirmed
+  FCC_API_URL: 'https://api.example.org'
 };
 
 describe('findEnvProblems', () => {
@@ -64,6 +66,11 @@ describe('findEnvProblems', () => {
     ]);
   });
 
+  it('requires FCC_API_URL in production', () => {
+    const env: NodeJS.ProcessEnv = { ...productionEnv, FCC_API_URL: undefined };
+    expect(findEnvProblems(env)).toEqual(['FCC_API_URL is not set']);
+  });
+
   it('rejects dev login mode in production', () => {
     const env: NodeJS.ProcessEnv = {
       ...productionEnv,
diff --git a/util/env.ts b/util/env.ts
index c7c9cf411..0961b311f 100644
--- a/util/env.ts
+++ b/util/env.ts
@@ -9,7 +9,8 @@ const ALWAYS_REQUIRED: string[] = [
 const PRODUCTION_REQUIRED: string[] = [
   'AUTH0_DOMAIN',
   'AUTH0_CLIENT_ID',
-  'AUTH0_CLIENT_SECRET'
+  'AUTH0_CLIENT_SECRET',
+  'FCC_API_URL'
 ];
 
 export function findEnvProblems(env: NodeJS.ProcessEnv): string[] {