diff --git a/src/Symfony/Component/Routing/Router.php b/src/Symfony/Component/Routing/Router.php
index 89b14925e7124..25b9456afc5d1 100644
--- a/src/Symfony/Component/Routing/Router.php
+++ b/src/Symfony/Component/Routing/Router.php
@@ -313,14 +313,12 @@ public function getGenerator()
 
         if (null === $this->options['cache_dir']) {
             $routes = $this->getRouteCollection();
-            $aliases = [];
             $compiled = is_a($this->options['generator_class'], CompiledUrlGenerator::class, true);
             if ($compiled) {
                 $generatorDumper = new CompiledUrlGeneratorDumper($routes);
-                $routes = $generatorDumper->getCompiledRoutes();
-                $aliases = $generatorDumper->getCompiledAliases();
+                $routes = array_merge($generatorDumper->getCompiledRoutes(), $generatorDumper->getCompiledAliases());
             }
-            $this->generator = new $this->options['generator_class'](array_merge($routes, $aliases), $this->context, $this->logger, $this->defaultLocale);
+            $this->generator = new $this->options['generator_class']($routes, $this->context, $this->logger, $this->defaultLocale);
         } else {
             $cache = $this->getConfigCacheFactory()->cache($this->options['cache_dir'].'/url_generating_routes.php',
                 function (ConfigCacheInterface $cache) {
diff --git a/src/Symfony/Component/Routing/Tests/RouterTest.php b/src/Symfony/Component/Routing/Tests/RouterTest.php
index e1800975b0c39..73a8ffd47816a 100644
--- a/src/Symfony/Component/Routing/Tests/RouterTest.php
+++ b/src/Symfony/Component/Routing/Tests/RouterTest.php
@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\Loader\LoaderInterface;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\Routing\Generator\CompiledUrlGenerator;
 use Symfony\Component\Routing\Generator\UrlGenerator;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 use Symfony\Component\Routing\Matcher\RequestMatcherInterface;
@@ -124,11 +125,24 @@ public function testGeneratorIsCreatedIfCacheIsNotConfigured()
     {
         $this->router->setOption('cache_dir', null);
 
+        $this->loader->expects($this->once())
+            ->method('load')->with('routing.yml', null)
+            ->willReturn(new RouteCollection());
+
+        $this->assertInstanceOf(CompiledUrlGenerator::class, $this->router->getGenerator());
+    }
+
+    public function testGeneratorIsCreatedIfCacheIsNotConfiguredNotCompiled()
+    {
+        $this->router->setOption('cache_dir', null);
+        $this->router->setOption('generator_class', UrlGenerator::class);
+
         $this->loader->expects($this->once())
             ->method('load')->with('routing.yml', null)
             ->willReturn(new RouteCollection());
 
         $this->assertInstanceOf(UrlGenerator::class, $this->router->getGenerator());
+        $this->assertNotInstanceOf(CompiledUrlGenerator::class, $this->router->getGenerator());
     }
 
     public function testMatchRequestWithUrlMatcherInterface()