diff --git a/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/NavigatorTest.kt b/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/NavigatorTest.kt
index 241fbb7e..eb68d8e8 100644
--- a/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/NavigatorTest.kt
+++ b/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/NavigatorTest.kt
@@ -21,6 +21,7 @@ import com.vaadin.flow.router.Route
 import com.vaadin.flow.router.RouteNotFoundError
 import com.vaadin.flow.server.VaadinRequest
 import com.vaadin.flow.server.auth.NavigationAccessControl
+import test.app.MyRouteNotFoundError
 import java.io.Serializable
 import java.security.Principal
 import java.util.function.Predicate
@@ -254,6 +255,61 @@ internal fun DynaNodeGroup.navigatorTest() {
             }
         }
     }
+    group("security2 - with all routes") {
+        beforeEach { MockVaadin.tearDown() }
+        afterEach { MockVaadin.tearDown() }
+
+        group("no user logged in") {
+            test("when access is rejected, redirect goes to WelcomeView") {
+                val routes = Routes().autoDiscoverViews()
+                routes.errorRoutes.remove(MyRouteNotFoundError::class.java)
+                routes.errorRoutes.add(MockRouteNotFoundError::class.java)
+                MockVaadin.setup(routes)
+
+                UI.getCurrent().addBeforeEnterListener(SimpleNavigationAccessControl().apply {
+                    setLoginView(WelcomeView::class.java)
+                })
+                navigateTo<TestingView>()
+                expectView<WelcomeView>()
+            }
+            test("when access is rejected and no login view is set, redirects to MockRouteNotFoundError") {
+                val routes = Routes().autoDiscoverViews()
+                routes.errorRoutes.remove(MyRouteNotFoundError::class.java)
+                routes.errorRoutes.add(MockRouteNotFoundError::class.java)
+                MockVaadin.setup(routes)
+
+                UI.getCurrent().addBeforeEnterListener(SimpleNavigationAccessControl())
+                expectThrows<NotFoundException>("No route found for 'testing': Consider adding one of the following annotations to make the view accessible: @AnonymousAllowed, @PermitAll, @RolesAllowed.") {
+                    navigateTo<TestingView>()
+                }
+            }
+        }
+        group("user logged in") {
+            test("when access is rejected, default handler redirects to MockRouteNotFoundError") {
+                val routes = Routes().autoDiscoverViews()
+                routes.errorRoutes.remove(MyRouteNotFoundError::class.java)
+                routes.errorRoutes.add(MockRouteNotFoundError::class.java)
+                routes.errorRoutes.remove(MockRouteAccessDeniedError::class.java)
+                MockVaadin.setup(routes)
+
+                UI.getCurrent().addBeforeEnterListener(SimpleNavigationAccessControl("admin"))
+                expectThrows<NotFoundException>("No route found for 'testing': Consider adding one of the following annotations to make the view accessible: @AnonymousAllowed, @PermitAll, @RolesAllowed.") {
+                    navigateTo<TestingView>()
+                }
+            }
+            test("when access is rejected, Karibu's MockRouteAccessDeniedError throws AccessDeniedException") {
+                val routes = Routes().autoDiscoverViews()
+                routes.errorRoutes.remove(MyRouteNotFoundError::class.java)
+                routes.errorRoutes.add(MockRouteNotFoundError::class.java)
+                MockVaadin.setup(routes)
+
+                UI.getCurrent().addBeforeEnterListener(SimpleNavigationAccessControl("admin"))
+                expectThrows<AccessDeniedException>("Consider adding one of the following annotations to make the view accessible: @AnonymousAllowed, @PermitAll, @RolesAllowed") {
+                    navigateTo<TestingView>()
+                }
+            }
+        }
+    }
 }
 
 @Route("navigation-postpone")
diff --git a/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/RoutesTest.kt b/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/RoutesTest.kt
index cc2a5d35..625d685f 100644
--- a/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/RoutesTest.kt
+++ b/karibu-testing-v10/kt10-tests/src/main/kotlin/com/github/mvysny/kaributesting/v10/RoutesTest.kt
@@ -49,11 +49,7 @@ fun DynaNodeGroup.routesTestBatch() {
     // https://github.com/mvysny/karibu-testing/issues/50
     test("app-specific NotFoundException handler removes MockRouteNotFoundError") {
         val routes: Routes = Routes().autoDiscoverViews()
-        // Vaadin 24.3+ introduces additional route
-        val routeAccessDeniedError = if (VaadinVersion.get.isAtLeast(24, 3)) Class.forName("com.vaadin.flow.router.RouteAccessDeniedError") else null
-        val expectedRouteClasses =
-            setOf(ErrorView::class.java, InternalServerError::class.java, MyRouteNotFoundError::class.java, RouteNotFoundError::class.java, routeAccessDeniedError)
-                .filterNotNull().toSet()
+        val expectedRouteClasses = setOf(ErrorView::class.java, InternalServerError::class.java, MyRouteNotFoundError::class.java, MockRouteAccessDeniedError::class.java)
         expect(expectedRouteClasses) { routes.errorRoutes.toSet() }
         // make sure that Vaadin initializes properly with this set of views
         MockVaadin.setup(routes)
diff --git a/karibu-testing-v10/src/main/kotlin/com/github/mvysny/kaributesting/v10/Routes.kt b/karibu-testing-v10/src/main/kotlin/com/github/mvysny/kaributesting/v10/Routes.kt
index a69daa59..1db302a0 100644
--- a/karibu-testing-v10/src/main/kotlin/com/github/mvysny/kaributesting/v10/Routes.kt
+++ b/karibu-testing-v10/src/main/kotlin/com/github/mvysny/kaributesting/v10/Routes.kt
@@ -1,6 +1,7 @@
 package com.github.mvysny.kaributesting.v10
 
 import com.github.mvysny.kaributesting.v10.mock.MockVaadin19
+import com.github.mvysny.kaributools.VaadinVersion
 import com.vaadin.flow.component.Component
 import com.vaadin.flow.component.Tag
 import com.vaadin.flow.router.*
@@ -83,6 +84,13 @@ public data class Routes(
             }
         }
 
+        // remove @DefaultErrorHandler RouteAccessDeniedError and RouteNotFoundError so that they're replaced with Karibu's Mock counterparts
+        // which perform better logging
+        errorRoutes.remove(RouteNotFoundError::class.java)
+        if (VaadinVersion.get.isAtLeast(24, 3)) {
+            errorRoutes.remove(Class.forName("com.vaadin.flow.router.RouteAccessDeniedError"))
+        }
+
         // https://github.com/mvysny/karibu-testing/issues/50
         // if the app defines its own NotFoundException handler, remove MockRouteNotFoundError
         if (errorRoutes.any { it != MockRouteNotFoundError::class.java && it.isRouteNotFound }) {