diff --git a/app/assets/javascripts/discourse/controllers/exception.js.es6 b/app/assets/javascripts/discourse/controllers/exception.js.es6
index a44d0b9c93..dc265426a0 100644
--- a/app/assets/javascripts/discourse/controllers/exception.js.es6
+++ b/app/assets/javascripts/discourse/controllers/exception.js.es6
@@ -32,6 +32,7 @@ export default Ember.Controller.extend({
     if (this.get('thrown.jqTextStatus') === "timeout") return true;
     return false;
   }.property(),
+
   isNotFound: Em.computed.equal('thrown.status', 404),
   isForbidden: Em.computed.equal('thrown.status', 403),
   isServer: Em.computed.gte('thrown.status', 500),
diff --git a/app/assets/javascripts/discourse/routes/app-route-map.js.es6 b/app/assets/javascripts/discourse/routes/app-route-map.js.es6
index 8ec183d8b5..72dca540a1 100644
--- a/app/assets/javascripts/discourse/routes/app-route-map.js.es6
+++ b/app/assets/javascripts/discourse/routes/app-route-map.js.es6
@@ -1,6 +1,7 @@
 export default function() {
   // Error page
   this.route('exception', { path: '/exception' });
+  this.route('exception-unknown', { path: '/404' });
 
   this.route('about', { path: '/about', resetNamespace: true });
 
diff --git a/app/assets/javascripts/discourse/routes/application.js.es6 b/app/assets/javascripts/discourse/routes/application.js.es6
index a035ef6c70..599adde72c 100644
--- a/app/assets/javascripts/discourse/routes/application.js.es6
+++ b/app/assets/javascripts/discourse/routes/application.js.es6
@@ -83,6 +83,10 @@ const ApplicationRoute = Discourse.Route.extend(OpenComposer, {
         c.error(xhrOrErr);
       }
 
+      if (xhrOrErr && xhrOrErr.status === 404) {
+        return this.transitionTo('exception-unknown');
+      }
+
       exceptionController.setProperties({ lastTransition: transition, thrown: xhrOrErr });
 
       this.intermediateTransitionTo('exception');
diff --git a/app/assets/javascripts/discourse/routes/exception-unknown.js.es6 b/app/assets/javascripts/discourse/routes/exception-unknown.js.es6
new file mode 100644
index 0000000000..a3d0778d30
--- /dev/null
+++ b/app/assets/javascripts/discourse/routes/exception-unknown.js.es6
@@ -0,0 +1,7 @@
+import UnknownRoute from 'discourse/routes/unknown';
+
+export default UnknownRoute.extend({
+  renderTemplate() {
+    this.render('unknown');
+  }
+});