diff --git a/packages/e2e-test/src/commands/runCommand.ts b/packages/e2e-test/src/commands/runCommand.ts
index 170d1252bf..22d0867c4b 100644
--- a/packages/e2e-test/src/commands/runCommand.ts
+++ b/packages/e2e-test/src/commands/runCommand.ts
@@ -456,6 +456,8 @@ async function testBackendStart(appDir: string, ...args: string[]) {
     env: {
       ...process.env,
       GITHUB_TOKEN: 'abc',
+      // Ensure that the backend fails on unhandledRejection errors.
+      NODE_ENV: 'test',
       // TODO: Default auth policy is disabled for e2e tests - replace this with external service auth
       APP_CONFIG_backend_auth_dangerouslyDisableDefaultAuthPolicy: 'true',
     },