diff --git a/.gitattributes b/.gitattributes
index 72b1777..476fb15 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -2,7 +2,6 @@
 .gitignore export-ignore
 *.md export-ignore
 /tests export-ignore
-/easy-ci.php export-ignore
 /ecs.php export-ignore
 /phpstan.neon export-ignore
 /rector.php export-ignore
diff --git a/.github/workflows/code_analysis.yaml b/.github/workflows/code_analysis.yaml
index 55c4b3b..44964bc 100644
--- a/.github/workflows/code_analysis.yaml
+++ b/.github/workflows/code_analysis.yaml
@@ -46,7 +46,7 @@ jobs:
 
                     -
                         name: 'Check Active Classes'
-                        run: vendor/bin/easy-ci check-active-class src --ansi
+                        run: vendor/bin/class-leak check src --ansi --skip-type="\Symplify\PhpConfigPrinter\Contract\Converter\ServiceOptionsKeyYamlToPhpFactoryInterface" --skip-type="\Symplify\PhpConfigPrinter\Contract\RoutingCaseConverterInterface" --skip-type="\Symplify\PhpConfigPrinter\Contract\CaseConverterInterface"
 
         name: ${{ matrix.actions.name }}
         runs-on: ubuntu-latest
diff --git a/composer.json b/composer.json
index 51b86ee..0aadc52 100644
--- a/composer.json
+++ b/composer.json
@@ -20,6 +20,7 @@
         "symplify/phpstan-extensions": "^11.2",
         "symplify/phpstan-rules": "^12.0",
         "symplify/symplify-kernel": "^11.0",
+        "tomasvotruba/class-leak": "0.1.1.72",
         "tomasvotruba/unused-public": "^0.2.0"
     },
     "autoload": {
diff --git a/easy-ci.php b/easy-ci.php
deleted file mode 100644
index fbb0017..0000000
--- a/easy-ci.php
+++ /dev/null
@@ -1,56 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-use Symplify\EasyCI\Config\EasyCIConfig;
-use Symplify\PhpConfigPrinter\CaseConverter\AliasCaseConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\ClassServiceCaseConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\ConfiguredServiceCaseConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\ExtensionConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\ImportCaseConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\NameOnlyServiceCaseConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\ParameterCaseConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\ResourceCaseConverter;
-use Symplify\PhpConfigPrinter\CaseConverter\ServicesDefaultsCaseConverter;
-use Symplify\PhpConfigPrinter\RoutingCaseConverter\ConditionalEnvRoutingCaseConverter;
-use Symplify\PhpConfigPrinter\RoutingCaseConverter\ImportRoutingCaseConverter;
-use Symplify\PhpConfigPrinter\RoutingCaseConverter\PathRoutingCaseConverter;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\AbstractServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\ArgumentsServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\AutowiringTypesOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\BindAutowireAutoconfigureServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\CallsServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\DecoratesServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\DeprecatedServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\FactoryConfiguratorServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\ParentLazyServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\PropertiesServiceOptionKeyYamlToPhpFactory;
-use Symplify\PhpConfigPrinter\ServiceOptionConverter\SharedPublicServiceOptionKeyYamlToPhpFactory;
-
-return static function (EasyCIConfig $easyCIConfig): void {
-    $easyCIConfig->typesToSkip([
-        AliasCaseConverter::class,
-        ClassServiceCaseConverter::class,
-        ConfiguredServiceCaseConverter::class,
-        ExtensionConverter::class,
-        ImportCaseConverter::class,
-        NameOnlyServiceCaseConverter::class,
-        ParameterCaseConverter::class,
-        ResourceCaseConverter::class,
-        ServicesDefaultsCaseConverter::class,
-        ConditionalEnvRoutingCaseConverter::class,
-        ImportRoutingCaseConverter::class,
-        PathRoutingCaseConverter::class,
-        AbstractServiceOptionKeyYamlToPhpFactory::class,
-        ArgumentsServiceOptionKeyYamlToPhpFactory::class,
-        AutowiringTypesOptionKeyYamlToPhpFactory::class,
-        BindAutowireAutoconfigureServiceOptionKeyYamlToPhpFactory::class,
-        CallsServiceOptionKeyYamlToPhpFactory::class,
-        DecoratesServiceOptionKeyYamlToPhpFactory::class,
-        DeprecatedServiceOptionKeyYamlToPhpFactory::class,
-        FactoryConfiguratorServiceOptionKeyYamlToPhpFactory::class,
-        ParentLazyServiceOptionKeyYamlToPhpFactory::class,
-        PropertiesServiceOptionKeyYamlToPhpFactory::class,
-        SharedPublicServiceOptionKeyYamlToPhpFactory::class,
-    ]);
-};
diff --git a/ecs.php b/ecs.php
index bb42212..862b15d 100644
--- a/ecs.php
+++ b/ecs.php
@@ -9,7 +9,6 @@
     $ecsConfig->paths([
         __DIR__ . '/ecs.php',
         __DIR__ . '/rector.php',
-        __DIR__ . '/easy-ci.php',
         __DIR__ . '/src',
         __DIR__ . '/tests',
     ]);
diff --git a/src/CaseConverter/AliasCaseConverter.php b/src/CaseConverter/AliasCaseConverter.php
index 7cfda73..fcf60bf 100644
--- a/src/CaseConverter/AliasCaseConverter.php
+++ b/src/CaseConverter/AliasCaseConverter.php
@@ -114,10 +114,10 @@ private function createAliasNode(string $key, string $fullClassName, mixed $serv
 
     private function createFromClassLike(string $key, mixed $values, Variable $servicesVariable): Expression
     {
-        $classReference = $this->commonNodeFactory->createClassReference($key);
+        $classConstFetch = $this->commonNodeFactory->createClassReference($key);
 
         $argValues = [];
-        $argValues[] = $classReference;
+        $argValues[] = $classConstFetch;
         $argValues[] = $values[MethodName::ALIAS] ?? $values;
 
         $args = $this->argsNodeFactory->createFromValues($argValues, true);
diff --git a/src/NodeFactory/ContainerConfiguratorReturnClosureFactory.php b/src/NodeFactory/ContainerConfiguratorReturnClosureFactory.php
index fc222e7..3b0193b 100644
--- a/src/NodeFactory/ContainerConfiguratorReturnClosureFactory.php
+++ b/src/NodeFactory/ContainerConfiguratorReturnClosureFactory.php
@@ -134,7 +134,7 @@ private function resolveExpressionWhenAtEnv(
             $args = $expr->getArgs();
 
             if (! isset($args[1]) || ! $args[1]->value instanceof Array_ || ! isset($args[1]->value->items[0])
-                || ! $args[1]->value->items[0] instanceof ArrayItem || $args[1]->value->items[0]->key === null) {
+                || ! $args[1]->value->items[0] instanceof ArrayItem || ! $args[1]->value->items[0]->key instanceof Expr) {
                 throw new ShouldNotHappenException();
             }
 
diff --git a/src/NodeFactory/Service/SingleServicePhpNodeFactory.php b/src/NodeFactory/Service/SingleServicePhpNodeFactory.php
index 1e28651..05d8326 100644
--- a/src/NodeFactory/Service/SingleServicePhpNodeFactory.php
+++ b/src/NodeFactory/Service/SingleServicePhpNodeFactory.php
@@ -87,7 +87,7 @@ private function createCallMethodCall(mixed $call, MethodCall $methodCall): Meth
         $args[] = new Arg($argumentsExpr);
 
         $returnCloneExpr = $this->resolveCallReturnClone($call);
-        if ($returnCloneExpr !== null) {
+        if ($returnCloneExpr instanceof Expr) {
             $args[] = new Arg($returnCloneExpr);
         }