diff --git a/ionic/components/nav/nav-controller.ts b/ionic/components/nav/nav-controller.ts
index c1fc8f77de..0859733efe 100644
--- a/ionic/components/nav/nav-controller.ts
+++ b/ionic/components/nav/nav-controller.ts
@@ -450,7 +450,7 @@ export class NavController extends Ion {
         return done();
       }
 
-      this._setZIndex(enteringView.instance, leavingView.instance, opts.direction);
+      this._setZIndex(enteringView.instance, leavingView && leavingView.instance, opts.direction);
 
       this._zone.runOutsideAngular(() => {