diff --git a/src/main/window/privileged-window-navigation.test.ts b/src/main/window/privileged-window-navigation.test.ts
new file mode 100644
index 00000000000..579d830f244
--- /dev/null
+++ b/src/main/window/privileged-window-navigation.test.ts
@@ -0,0 +1,96 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const openExternal = vi.fn()
+vi.mock('electron', () => ({
+  shell: { openExternal: (url: string) => openExternal(url) }
+}))
+
+import { installPrivilegedWindowNavigationPolicy } from './privileged-window-navigation'
+
+describe('privileged window navigation policy', () => {
+  function createFixture(currentUrl: string) {
+    const handlers = new Map<string, (...args: unknown[]) => void>()
+    const contents = {
+      getURL: () => currentUrl,
+      setWindowOpenHandler: vi.fn(),
+      on: vi.fn((event: string, handler: (...args: unknown[]) => void) => {
+        handlers.set(event, handler)
+      })
+    }
+    installPrivilegedWindowNavigationPolicy(contents as never)
+    return {
+      willNavigate(url: string) {
+        const event = { preventDefault: vi.fn() }
+        const handler = handlers.get('will-navigate')
+        // Why: the allow-cases assert preventDefault was *not* called, so a missing
+        // handler would pass them vacuously.
+        if (!handler) {
+          throw new Error('no will-navigate handler was registered')
+        }
+        handler(event, url)
+        return event
+      }
+    }
+  }
+
+  beforeEach(() => {
+    openExternal.mockClear()
+  })
+
+  it('lets the packaged renderer document reload itself', () => {
+    const appUrl =
+      'file:///Applications/Orca.app/Contents/Resources/app.asar/out/renderer/index.html'
+    const event = createFixture(appUrl).willNavigate(appUrl)
+
+    expect(event.preventDefault).not.toHaveBeenCalled()
+    expect(openExternal).not.toHaveBeenCalled()
+  })
+
+  it('still blocks and hands off an external http target', () => {
+    const appUrl =
+      'file:///Applications/Orca.app/Contents/Resources/app.asar/out/renderer/index.html'
+    const event = createFixture(appUrl).willNavigate('https://example.com/')
+
+    expect(event.preventDefault).toHaveBeenCalled()
+    expect(openExternal).toHaveBeenCalledWith('https://example.com/')
+  })
+
+  it('lets the dev renderer origin navigate but blocks foreign documents', () => {
+    const fixture = createFixture('http://localhost:5173/')
+
+    expect(
+      fixture.willNavigate('http://localhost:5173/index.html').preventDefault
+    ).not.toHaveBeenCalled()
+    expect(fixture.willNavigate('https://example.com/').preventDefault).toHaveBeenCalled()
+    expect(
+      fixture.willNavigate('blob:http://localhost:5173/attacker-document').preventDefault
+    ).toHaveBeenCalled()
+  })
+
+  // Why: the packaged file: path is the whole privilege boundary, so a foreign host or a
+  // non-file scheme that reuses it must not read as "our own document".
+  it('blocks a foreign file host and a data: URL that reuse the renderer path', () => {
+    const appUrl =
+      'file:///Applications/Orca.app/Contents/Resources/app.asar/out/renderer/index.html'
+    const fixture = createFixture(appUrl)
+
+    expect(
+      fixture.willNavigate(
+        'file://evil.example/Applications/Orca.app/Contents/Resources/app.asar/out/renderer/index.html'
+      ).preventDefault
+    ).toHaveBeenCalled()
+    expect(
+      fixture.willNavigate('data:text/html,<script>1</script>').preventDefault
+    ).toHaveBeenCalled()
+    expect(openExternal).not.toHaveBeenCalled()
+  })
+
+  it('still blocks navigation to an unrelated local file', () => {
+    const appUrl =
+      'file:///Applications/Orca.app/Contents/Resources/app.asar/out/renderer/index.html'
+    const event = createFixture(appUrl).willNavigate('file:///Users/someone/.ssh/id_rsa')
+
+    expect(event.preventDefault).toHaveBeenCalled()
+    expect(openExternal).not.toHaveBeenCalled()
+  })
+})
diff --git a/src/main/window/privileged-window-navigation.ts b/src/main/window/privileged-window-navigation.ts
index a5afbbe0a98..d11268f0340 100644
--- a/src/main/window/privileged-window-navigation.ts
+++ b/src/main/window/privileged-window-navigation.ts
@@ -1,6 +1,6 @@
 import { shell, type WebContents } from 'electron'
-import { is } from '@electron-toolkit/utils'
 import { normalizeExternalBrowserUrl } from '../../shared/browser-url'
+import { isRendererDocumentNavigation } from './renderer-document-navigation'
 
 /** Keep remote documents from inheriting an Orca window's privileged preload. */
 export function installPrivilegedWindowNavigationPolicy(contents: WebContents): void {
@@ -13,19 +13,13 @@ export function installPrivilegedWindowNavigationPolicy(contents: WebContents):
   })
 
   contents.on('will-navigate', (event, url) => {
+    // Why: location.reload() is a renderer-initiated navigation, so blocking it here
+    // silently kills the lazy-chunk recovery reload with no unload-prevented signal.
+    if (isRendererDocumentNavigation(contents.getURL(), url)) {
+      return
+    }
     const externalUrl = normalizeExternalBrowserUrl(url)
     if (externalUrl) {
-      if (is.dev && process.env.ELECTRON_RENDERER_URL) {
-        try {
-          const target = new URL(externalUrl)
-          const allowed = new URL(process.env.ELECTRON_RENDERER_URL)
-          if (target.origin === allowed.origin) {
-            return
-          }
-        } catch {
-          // Fall through and block malformed navigation targets.
-        }
-      }
       void shell.openExternal(externalUrl)
     }
     event.preventDefault()
diff --git a/src/main/window/renderer-document-navigation.ts b/src/main/window/renderer-document-navigation.ts
index 4179e24a511..50fb128b633 100644
--- a/src/main/window/renderer-document-navigation.ts
+++ b/src/main/window/renderer-document-navigation.ts
@@ -1,6 +1,12 @@
 import type { WebContents } from 'electron'
 
-function isRendererDocumentNavigation(currentUrl: string, nextUrl: string): boolean {
+/**
+ * True when the target stays inside the window's own privileged document: for `file:`
+ * the exact same host+path (query/hash may differ, as a reload keeps them), for http(s)
+ * the same origin. Also gates preload privilege in installPrivilegedWindowNavigationPolicy,
+ * so loosening it past a same-origin document hands a foreign page the Orca bridge.
+ */
+export function isRendererDocumentNavigation(currentUrl: string, nextUrl: string): boolean {
   try {
     const current = new URL(currentUrl)
     const next = new URL(nextUrl)
@@ -13,6 +19,7 @@ function isRendererDocumentNavigation(currentUrl: string, nextUrl: string): bool
     }
     return (
       (current.protocol === 'http:' || current.protocol === 'https:') &&
+      (next.protocol === 'http:' || next.protocol === 'https:') &&
       next.origin === current.origin
     )
   } catch {