diff --git a/lib/host/auth.sx b/lib/host/auth.sx
index eca0b994..499808de 100644
--- a/lib/host/auth.sx
+++ b/lib/host/auth.sx
@@ -48,7 +48,10 @@
             (input :type "hidden" :name "next" :value (unquote next-path))
             (p (input :name "username" :placeholder "username"))
             (p (input :name "password" :type "password" :placeholder "password"))
-            (p (button :type "submit" "Log in"))))))))
+            (p (button :type "submit" "Log in")))
+          ;; a way back into the app — the login shell is a standalone page (no persistent
+          ;; nav), so without this a logged-out user who followed a guarded link is stranded.
+          (p :style "margin-top:1em" (a :href "/" "← Home")))))))
 
 ;; ── GET /login — login form, honouring ?next= (where to go after login) ─────
 (define host/login-page
@@ -137,5 +140,14 @@
       (fn (req)
         (let ((principal (host/-principal-of req resolve)))
           (if (or (nil? principal) (= principal ""))
-            (dream-redirect (str "/login?next=" (host/-safe-next (dream-path req))))
+            (let ((login-url (str "/login?next=" (host/-safe-next (dream-path req)))))
+              ;; A BOOSTED (SX-Request) request can't be answered with a 303: the browser's
+              ;; fetch follows the redirect WITHOUT the SX-Request header, so /login returns
+              ;; the full HTML shell, which morphed into #content DESTROYS the SPA swap target
+              ;; (every later boosted nav then has nowhere to swap — "nothing happens"). Return
+              ;; an SX-Redirect header instead — the engine does a FULL navigation to /login (a
+              ;; fresh shell). A non-boosted request still gets a plain 303.
+              (if (= (dream-header req "sx-request") "true")
+                (dream-response 200 {:sx-redirect login-url} "")
+                (dream-redirect login-url)))
             (next (assoc req :dream-principal principal))))))))
diff --git a/lib/host/playwright/boost-nav.spec.js b/lib/host/playwright/boost-nav.spec.js
index 59506e39..028e522c 100644
--- a/lib/host/playwright/boost-nav.spec.js
+++ b/lib/host/playwright/boost-nav.spec.js
@@ -34,4 +34,26 @@ test.describe('boosted navigation (browser-only)', () => {
     expect(page.url()).not.toContain('/tags');
     expect(page.url()).toContain('/compose-demo/edit');
   });
+
+  test('a guarded route reached via boost does a clean full-nav to /login (no clobbered SPA), and Home works from there', async ({ page }) => {
+    test.setTimeout(90000);
+    await page.goto(BASE + '/');
+    await waitReady(page);
+    // boosted nav home -> post
+    await page.locator('a[href="/compose-demo/"]').first().click();
+    await expect(page.locator('body')).toContainText('composition object', { timeout: 15000 });
+    // click "edit" (guarded, logged out). A 303 would be followed by the fetch WITHOUT the
+    // SX-Request header -> /login returns the full shell, which morphed into #content
+    // DESTROYS the swap target (then nothing navigates). The fix returns SX-Redirect, so the
+    // engine does a FULL navigation to a real /login page.
+    await page.locator('a[href="/compose-demo/edit"]').click();
+    await page.waitForTimeout(3500);
+    expect(new URL(page.url()).pathname).toBe('/login');
+    await expect(page.locator('body')).toContainText('Log in');
+    // and the login page offers a way back Home that works (the reported "Home does nothing").
+    await page.locator('a[href="/"]').first().click();
+    await page.waitForTimeout(3000);
+    await expect(page.locator('body')).toContainText('Posts', { timeout: 12000 });
+    expect(new URL(page.url()).pathname).toBe('/');
+  });
 });