diff --git a/tests/Extension/EscaperTest.php b/tests/Extension/EscaperTest.php
index c465789153..d8fedc64e2 100644
--- a/tests/Extension/EscaperTest.php
+++ b/tests/Extension/EscaperTest.php
@@ -17,7 +17,7 @@
 use Twig\Extension\EscaperExtension;
 use Twig\Loader\LoaderInterface;
 
-class Twig_Tests_Extension_EscaperTest extends TestCase
+class EscaperTest extends TestCase
 {
     /**
      * All character encodings supported by htmlspecialchars().
diff --git a/tests/Fixtures/functions/include/template_instance.test b/tests/Fixtures/functions/include/template_instance.test
index 4c8b450835..be18d244ac 100644
--- a/tests/Fixtures/functions/include/template_instance.test
+++ b/tests/Fixtures/functions/include/template_instance.test
@@ -1,5 +1,5 @@
 --TEST--
-"include" function accepts Twig_Template instance
+"include" function accepts Twig\Template instance
 --TEMPLATE--
 {{ include(foo) }} FOO
 --TEMPLATE(foo.twig)--
diff --git a/tests/Fixtures/tags/inheritance/parent_as_template_wrapper.test b/tests/Fixtures/tags/inheritance/parent_as_template_wrapper.test
index 1aaed556c5..cf257f25dc 100644
--- a/tests/Fixtures/tags/inheritance/parent_as_template_wrapper.test
+++ b/tests/Fixtures/tags/inheritance/parent_as_template_wrapper.test
@@ -1,5 +1,5 @@
 --TEST--
-"extends" tag with a parent as a Twig_TemplateWrapper instance
+"extends" tag with a parent as a Twig\TemplateWrapper instance
 --TEMPLATE--
 {% extends foo %}
 
diff --git a/tests/Fixtures/tags/inheritance/template_instance.test b/tests/Fixtures/tags/inheritance/template_instance.test
index a5a223886d..b9009e5df5 100644
--- a/tests/Fixtures/tags/inheritance/template_instance.test
+++ b/tests/Fixtures/tags/inheritance/template_instance.test
@@ -1,5 +1,5 @@
 --TEST--
-"extends" tag accepts Twig_Template instance
+"extends" tag accepts Twig\Template instance
 --TEMPLATE--
 {% extends foo %}
 
diff --git a/tests/Node/Expression/CallTest.php b/tests/Node/Expression/CallTest.php
index 10fa00bea6..4705120764 100644
--- a/tests/Node/Expression/CallTest.php
+++ b/tests/Node/Expression/CallTest.php
@@ -125,10 +125,10 @@ public function customFunctionWithArbitraryArguments()
     public function testResolveArgumentsWithMissingParameterForArbitraryArgumentsOnFunction()
     {
         $this->expectException(\LogicException::class);
-        $this->expectExceptionMessageMatches('#^The last parameter of "Twig\\\\Tests\\\\Node\\\\Expression\\\\custom_Twig_Tests_Node_Expression_CallTest_function" for function "foo" must be an array with default value, eg\\. "array \\$arg \\= \\[\\]"\\.$#');
+        $this->expectExceptionMessageMatches('#^The last parameter of "Twig\\\\Tests\\\\Node\\\\Expression\\\\custom_call_test_function" for function "foo" must be an array with default value, eg\\. "array \\$arg \\= \\[\\]"\\.$#');
 
         $node = new Node_Expression_Call([], ['type' => 'function', 'name' => 'foo', 'is_variadic' => true]);
-        $node->getArguments('Twig\Tests\Node\Expression\custom_Twig_Tests_Node_Expression_CallTest_function', []);
+        $node->getArguments('Twig\Tests\Node\Expression\custom_call_test_function', []);
     }
 
     public function testResolveArgumentsWithMissingParameterForArbitraryArgumentsOnObject()
@@ -156,6 +156,6 @@ public function __invoke($required)
     }
 }
 
-function custom_Twig_Tests_Node_Expression_CallTest_function($required)
+function custom_call_test_function($required)
 {
 }
diff --git a/tests/Util/DeprecationCollectorTest.php b/tests/Util/DeprecationCollectorTest.php
index 7b5794d83c..18f889f6a4 100644
--- a/tests/Util/DeprecationCollectorTest.php
+++ b/tests/Util/DeprecationCollectorTest.php
@@ -28,7 +28,7 @@ public function testCollect()
         $twig->addFunction(new TwigFunction('deprec', [$this, 'deprec'], ['deprecated' => '1.1']));
 
         $collector = new DeprecationCollector($twig);
-        $deprecations = $collector->collect(new Twig_Tests_Util_Iterator());
+        $deprecations = $collector->collect(new Iterator());
 
         $this->assertEquals(['Twig Function "deprec" is deprecated since version 1.1 in deprec.twig at line 1.'], $deprecations);
     }
@@ -38,7 +38,7 @@ public function deprec()
     }
 }
 
-class Twig_Tests_Util_Iterator implements \IteratorAggregate
+class Iterator implements \IteratorAggregate
 {
     public function getIterator(): \Traversable
     {