diff --git a/.travis.yml b/.travis.yml
index d6bea509a1..73fe5d219c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,9 +29,6 @@ matrix:
           env: deps=high
         - php: 7.3
           env: deps=low
-        - php: 7.4snapshot
-    allow_failures:
-    - php: 7.4snapshot
     fast_finish: true
 
 cache:
diff --git a/composer.json b/composer.json
index de4ec7f61c..1a7c9d4f53 100644
--- a/composer.json
+++ b/composer.json
@@ -114,7 +114,7 @@
         "psr/http-client": "^1.0",
         "psr/simple-cache": "^1.0",
         "egulias/email-validator": "~1.2,>=1.2.8|~2.0",
-        "symfony/phpunit-bridge": "^3.4.19|^4.1.8|~5.0",
+        "symfony/phpunit-bridge": "^3.4.31|^4.3.4|~5.0",
         "symfony/security-acl": "~2.8|~3.0",
         "phpdocumentor/reflection-docblock": "^3.0|^4.0"
     },
diff --git a/phpunit b/phpunit
index 7b0b47cf7b..b2883a1e05 100755
--- a/phpunit
+++ b/phpunit
@@ -8,8 +8,8 @@ if (!file_exists(__DIR__.'/vendor/symfony/phpunit-bridge/bin/simple-phpunit')) {
     exit(1);
 }
 if (!getenv('SYMFONY_PHPUNIT_VERSION')) {
-    if (\PHP_VERSION_ID >= 70400) {
-        putenv('SYMFONY_PHPUNIT_VERSION=8.2');
+    if (\PHP_VERSION_ID >= 70200) {
+        putenv('SYMFONY_PHPUNIT_VERSION=8.3');
     } elseif (\PHP_VERSION_ID >= 70000) {
         putenv('SYMFONY_PHPUNIT_VERSION=6.5');
     }
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/Routing/LegacyRouteLoaderContainerTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/Routing/LegacyRouteLoaderContainerTest.php
index cd002453ba..b0492efd89 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/Routing/LegacyRouteLoaderContainerTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/Routing/LegacyRouteLoaderContainerTest.php
@@ -39,7 +39,7 @@ class LegacyRouteLoaderContainerTest extends TestCase
     /**
      * {@inheritdoc}
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->container = new Container();
         $this->container->set('foo', new \stdClass());
diff --git a/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php b/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
index 9b633eaa0d..447df4ae8f 100644
--- a/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
+++ b/src/Symfony/Component/HttpKernel/Controller/ContainerControllerResolver.php
@@ -47,6 +47,8 @@ class ContainerControllerResolver extends ControllerResolver
      */
     protected function instantiateController(string $class)
     {
+        $class = ltrim($class, '\\');
+
         if ($this->container->has($class)) {
             return $this->container->get($class);
         }
diff --git a/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php b/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php
index 16779be286..c39dac3ca5 100644
--- a/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/Controller/ContainerControllerResolverTest.php
@@ -119,6 +119,36 @@ class ContainerControllerResolverTest extends ControllerResolverTest
         $this->assertSame($service, $controller);
     }
 
+    /**
+     * @dataProvider getControllers
+     */
+    public function testInstantiateControllerWhenControllerStartsWithABackslash($controller)
+    {
+        $service = new ControllerTestService('foo');
+        $class = ControllerTestService::class;
+
+        $container = $this->createMockContainer();
+        $container->expects($this->once())->method('has')->with($class)->willReturn(true);
+        $container->expects($this->once())->method('get')->with($class)->willReturn($service);
+
+        $resolver = $this->createControllerResolver(null, $container);
+        $request = Request::create('/');
+        $request->attributes->set('_controller', $controller);
+
+        $controller = $resolver->getController($request);
+
+        $this->assertInstanceOf(ControllerTestService::class, $controller[0]);
+        $this->assertSame('action', $controller[1]);
+    }
+
+    public function getControllers()
+    {
+        return [
+            ['\\'.ControllerTestService::class.'::action'],
+            ['\\'.ControllerTestService::class.':action'],
+        ];
+    }
+
     public function testExceptionWhenUsingRemovedControllerServiceWithClassNameAsName()
     {
         $this->expectException('InvalidArgumentException');