diff --git a/packages/cli/src/commands/login.test.ts b/packages/cli/src/commands/login.test.ts
new file mode 100644
index 00000000..dc5ea082
--- /dev/null
+++ b/packages/cli/src/commands/login.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest';
+import { loginCmd } from './login.js';
+
+// Regression guard for the `--no-browser` flag.
+//
+// Commander derives a boolean option named `browser` from `--no-browser` and defaults
+// it to `true`. Passing an explicit default of `false` as the third argument overrides
+// that, so `opts.browser` resolves to `false` even when the user never passed the flag.
+// The action then evaluates `opts.browser !== false` as false and never opens the
+// verification URL, which silently disables auto-open for everyone and makes
+// `--no-browser` a no-op.
+describe('login command --no-browser option', () => {
+  it('does not declare an explicit default value', () => {
+    const option = loginCmd.options.find((candidate) => candidate.long === '--no-browser');
+    expect(option).toBeDefined();
+    expect(option?.attributeName()).toBe('browser');
+    expect(option?.defaultValue).toBeUndefined();
+  });
+
+  it('defaults browser to true when the flag is absent', () => {
+    loginCmd.parseOptions([]);
+    expect(loginCmd.opts().browser).toBe(true);
+  });
+
+  it('sets browser to false when --no-browser is passed', () => {
+    loginCmd.parseOptions(['--no-browser']);
+    expect(loginCmd.opts().browser).toBe(false);
+  });
+});
diff --git a/packages/cli/src/commands/login.ts b/packages/cli/src/commands/login.ts
index d6d4f702..e7e87e0a 100644
--- a/packages/cli/src/commands/login.ts
+++ b/packages/cli/src/commands/login.ts
@@ -15,7 +15,7 @@ import {
 // the user approves on the page (or until the code expires).
 export const loginCmd = new Command('login')
   .description('Pair this CLI with your sh1pt.com account')
-  .option('--no-browser', 'do not auto-open the verification URL', false)
+  .option('--no-browser', 'do not auto-open the verification URL')
   .action(async (opts: { browser: boolean }) => {
     const existing = await readCredentials();
     if (existing) {