diff --git a/packages/core/src/components/router/utils/dom.ts b/packages/core/src/components/router/utils/dom.ts
index 53a085f316..d124bce3c3 100644
--- a/packages/core/src/components/router/utils/dom.ts
+++ b/packages/core/src/components/router/utils/dom.ts
@@ -1,8 +1,8 @@
 import { breadthFirstSearch } from './common';
 import { NavOutlet, RouteChain } from './interfaces';
 
-export function writeNavState(root: HTMLElement, chain: RouteChain, index: number, direction: number): Promise<void> {
-  if (index >= chain.length) {
+export function writeNavState(root: HTMLElement, chain: RouteChain|null, index: number, direction: number): Promise<void> {
+  if (!chain || index >= chain.length) {
     return Promise.resolve();
   }
   const route = chain[index];