diff --git a/ember_debug/route-debug.js b/ember_debug/route-debug.js
index 45624b801a..9cdfea5c7f 100644
--- a/ember_debug/route-debug.js
+++ b/ember_debug/route-debug.js
@@ -36,7 +36,10 @@ export default class RouteDebug extends DebugPort {
   }
 
   get router() {
-    if (this.namespace?.owner.isDestroyed) {
+    if (
+      this.namespace?.owner.isDestroyed ||
+      this.namespace?.owner.isDestroying
+    ) {
       return null;
     }
     return this.namespace?.owner.lookup('router:main');
@@ -74,6 +77,12 @@ export default class RouteDebug extends DebugPort {
   }
 
   get routeTree() {
+    if (
+      this.namespace?.owner.isDestroyed ||
+      this.namespace?.owner.isDestroying
+    ) {
+      return null;
+    }
     if (!this._cachedRouteTree && this.router) {
       const router = this.router;
       const routerLib = router._routerMicrolib || router.router;