diff --git a/tests/unit/dev-origins-config.test.mjs b/tests/unit/dev-origins-config.test.mjs
new file mode 100644
index 0000000000..8b2708955e
--- /dev/null
+++ b/tests/unit/dev-origins-config.test.mjs
@@ -0,0 +1,11 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+test("next config allows loopback dev origins alongside LAN access", async () => {
+  const { default: nextConfig } = await import("../../next.config.mjs");
+
+  assert.equal(Array.isArray(nextConfig.allowedDevOrigins), true);
+  assert.equal(nextConfig.allowedDevOrigins.includes("localhost"), true);
+  assert.equal(nextConfig.allowedDevOrigins.includes("127.0.0.1"), true);
+  assert.equal(nextConfig.allowedDevOrigins.includes("192.168.*"), true);
+});