diff --git a/src/Routing/PageManagerRoutes.php b/src/Routing/PageManagerRoutes.php
index 103137f..b9c1680 100644
--- a/src/Routing/PageManagerRoutes.php
+++ b/src/Routing/PageManagerRoutes.php
@@ -56,9 +56,8 @@ protected function alterRoutes(RouteCollection $collection) {
       /** @var $entity \Drupal\page_manager\PageInterface */
 
       // If the page is disabled skip making a route for it.
-      if (!$entity->status() || $entity->isFallbackPage()) {
-        continue;
-      }
+      // @todo The fallback page logic seems backward.
+      $modify_collection = $entity->status() && !$entity->isFallbackPage();
 
       // Prepare the values that need to be altered for an existing page.
       $parameters = [
@@ -74,30 +73,34 @@ protected function alterRoutes(RouteCollection $collection) {
         $path = $collection_route->getPath();
         $parameters += $collection_route->getOption('parameters') ?: [];
 
-        $collection->remove($route_name);
+        if ($modify_collection) {
+          $collection->remove($route_name);
+        }
       }
       else {
         $route_name = "page_manager.page_view_$entity_id";
         $path = $entity->getPath();
       }
 
-      // Construct and add a new route.
-      $route = new Route(
-        $path,
-        [
-          '_entity_view' => 'page_manager_page',
-          'page_manager_page' => $entity_id,
-          '_title' => $entity->label(),
-        ],
-        [
-          '_entity_access' => 'page_manager_page.view',
-        ],
-        [
-          'parameters' => $parameters,
-          '_admin_route' => $entity->usesAdminTheme(),
-        ]
-      );
-      $collection->add($route_name, $route);
+      if ($modify_collection) {
+        // Construct and add a new route.
+        $route = new Route(
+          $path,
+          [
+            '_entity_view' => 'page_manager_page',
+            'page_manager_page' => $entity_id,
+            '_title' => $entity->label(),
+          ],
+          [
+            '_entity_access' => 'page_manager_page.view',
+          ],
+          [
+            'parameters' => $parameters,
+            '_admin_route' => $entity->usesAdminTheme(),
+          ]
+        );
+        $collection->add($route_name, $route);
+      }
     }
   }
 
diff --git a/tests/src/Unit/PageManagerRoutesTest.php b/tests/src/Unit/PageManagerRoutesTest.php
index 6df2457..3fe818a 100644
--- a/tests/src/Unit/PageManagerRoutesTest.php
+++ b/tests/src/Unit/PageManagerRoutesTest.php
@@ -230,6 +230,41 @@ public function providerTestAlterRoutesOverrideExisting() {
   }
 
   /**
+   * @covers ::alterRoutes
+   */
+  public function testAlterRoutesOverrideExistingDisabled() {
+    $page_path = '/page';
+    $existing_route_path = '/page';
+    $route_name = 'test_route';
+    // Set up a page with the same path as an existing route.
+    $page = $this->prophesize(PageInterface::class);
+    $page->status()->willReturn(FALSE);
+    $page->getPath()->willReturn($page_path);
+    $page->isFallbackPage()->willReturn(FALSE);
+    $page->label()->willReturn(NULL);
+    $page->usesAdminTheme()->willReturn(FALSE);
+
+    $this->pageStorage->loadMultiple()
+      ->willReturn(['page1' => $page->reveal()])
+      ->shouldBeCalledTimes(1);
+
+    $this->cacheTagsInvalidator->invalidateTags(["page_manager_route_name:$route_name"])->shouldBeCalledTimes(1);
+
+    $collection = new RouteCollection();
+    $existing_route = new Route($existing_route_path, [], [], ['parameters' => ['foo' => 'bar']]);
+    $collection->add($route_name, $existing_route);
+    $route_event = new RouteBuildEvent($collection);
+    $this->routeSubscriber->onAlterRoutes($route_event);
+
+    // The normal route name is not used, the existing route name is instead.
+    $this->assertSame(1, $collection->count());
+    $this->assertNull($collection->get('page_manager.page_view_page1'));
+
+    $route = $collection->get($route_name);
+    $this->assertSame($existing_route, $route);
+  }
+
+  /**
    * Asserts that a route object has the expected properties.
    *
    * @param \Symfony\Component\Routing\Route $route