diff --git a/scripts/format-scope.json b/scripts/format-scope.json
index a28a8c53c..40bca019a 100644
--- a/scripts/format-scope.json
+++ b/scripts/format-scope.json
@@ -1128,6 +1128,7 @@
   "src/dockerTrustedPeers.test.mjs",
   "src/cameraGlobeRotation.test.mjs",
   "src/cameraTilt.test.mjs",
+  "src/ui/shellFacade.test.mjs",
   "src/voice/globeResetConfirmation.test.mjs",
   "src/hudDms.test.mjs",
   "src/hudSummaryGate.test.mjs",
diff --git a/src/ui/shellFacade.js b/src/ui/shellFacade.js
index 95bf791d4..678b69c79 100644
--- a/src/ui/shellFacade.js
+++ b/src/ui/shellFacade.js
@@ -6,7 +6,7 @@
 export class ShellFacade {
   /** Observe camera ownership transfers through the navigation owner. */
   subscribeCameraHandoff(listener) {
-    return this._navigation.subscribeCameraHandoff(listener);
+    return this._navigation?.subscribeCameraHandoff(listener);
   }
 
   get _models3dEnabled() {
diff --git a/src/ui/shellFacade.test.mjs b/src/ui/shellFacade.test.mjs
new file mode 100644
index 000000000..abb892b37
--- /dev/null
+++ b/src/ui/shellFacade.test.mjs
@@ -0,0 +1,33 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { ShellFacade } from './shellFacade.js';
+
+// A shell assembled without its navigation owner (as unit tests build one
+// from the prototype) has no handoffs to report, like the facade's other
+// optional owners; the voice runner subscribes as it is created.
+test('camera handoffs without a navigation owner subscribe to nothing', () => {
+  const shell = Object.create(ShellFacade.prototype);
+  assert.equal(
+    shell.subscribeCameraHandoff(() => {}),
+    undefined,
+  );
+});
+
+test('camera handoffs reach listeners through the navigation owner', () => {
+  const listeners = new Set();
+  const shell = Object.create(ShellFacade.prototype);
+  shell._navigation = {
+    subscribeCameraHandoff(listener) {
+      listeners.add(listener);
+      return () => listeners.delete(listener);
+    },
+  };
+  let handoffs = 0;
+  const unsubscribe = shell.subscribeCameraHandoff(() => {
+    handoffs += 1;
+  });
+  for (const listener of listeners) listener();
+  assert.equal(handoffs, 1);
+  unsubscribe();
+  assert.equal(listeners.size, 0);
+});