diff --git a/src/helpers/updateCheckPolicy.js b/src/helpers/updateCheckPolicy.js
index 5c2698f39..34f5b9993 100644
--- a/src/helpers/updateCheckPolicy.js
+++ b/src/helpers/updateCheckPolicy.js
@@ -3,7 +3,9 @@
 // firewalled machines never surface a connection error dialog (#1605).
 // Only an explicit false disables — missing prefs (renderer sync not arrived
 // yet) keep check-by-default behavior.
-function appUpdatesEnabled({ notificationsEnabled, notifyUpdates } = {}) {
+function appUpdatesEnabled(prefs = {}) {
+  const { notificationsEnabled, notifyUpdates } =
+    prefs && typeof prefs === "object" ? prefs : {};
   return notificationsEnabled !== false && notifyUpdates !== false;
 }
 
diff --git a/test/helpers/updateCheckPolicy.test.js b/test/helpers/updateCheckPolicy.test.js
index e564f269e..0ef2f7b70 100644
--- a/test/helpers/updateCheckPolicy.test.js
+++ b/test/helpers/updateCheckPolicy.test.js
@@ -25,6 +25,9 @@ test("checks stay enabled by default before renderer prefs arrive", async () =>
   // Same tri-state convention as the other notification prefs: only an
   // explicit false disables; missing prefs keep check-by-default behavior.
   assert.equal(appUpdatesEnabled(undefined), true);
+  assert.equal(appUpdatesEnabled(null), true);
   assert.equal(appUpdatesEnabled({}), true);
+  assert.equal(appUpdatesEnabled("invalid"), true);
+  assert.equal(appUpdatesEnabled(123), true);
   assert.equal(appUpdatesEnabled({ notificationsEnabled: true, notifyUpdates: true }), true);
 });