diff --git a/src/Build.php b/src/Build.php
index 503fc3e..e4f39c7 100644
--- a/src/Build.php
+++ b/src/Build.php
@@ -12,17 +12,17 @@ public function __construct($name)
     {
         parent::__construct(
             $name,
-            \Closure::fromCallable([$this, 'compile'])->bindTo($this),
-            \Closure::fromCallable([$this, 'evaluate'])->bindTo($this)
+            $this->compile(...)->bindTo($this),
+            $this->evaluate(...)->bindTo($this)
         );
     }
 
-    private function compile(string $input, string ...$values)
+    private function compile(string ...$values): string
     {
         return sprintf('array_values(array_merge(%s))', implode(', ', $values));
     }
 
-    private function evaluate(array $context, array ...$values)
+    private function evaluate(array $context, array ...$values): array
     {
         return array_values(array_merge(...$values));
     }
diff --git a/src/Value.php b/src/Value.php
index d63f47f..6ff9305 100644
--- a/src/Value.php
+++ b/src/Value.php
@@ -1,40 +1,43 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Kiboko\Component\ExpressionLanguage\Akeneo;
 
 final class Value
 {
     public function __construct(
-        private mixed $value,
+        private readonly mixed $value,
         private ?string $scope = null,
         private ?string $locale = null,
-    ) {}
-    
+    ) {
+    }
+
     public function withScope(string $scope): self
     {
         $this->scope = $scope;
-        
+
         return $this;
     }
-    
+
     public function withoutScope(): self
     {
         $this->scope = null;
-        
+
         return $this;
     }
-    
+
     public function withLocale(string $locale): self
     {
         $this->locale = $locale;
-        
+
         return $this;
     }
-    
+
     public function withoutLocale(): self
     {
         $this->locale = null;
-        
+
         return $this;
     }
 
diff --git a/src/WithMultipleOption.php b/src/WithMultipleOption.php
index 67c849a..65fe654 100644
--- a/src/WithMultipleOption.php
+++ b/src/WithMultipleOption.php
@@ -12,32 +12,32 @@ public function __construct($name)
     {
         parent::__construct(
             $name,
-            \Closure::fromCallable([$this, 'compile'])->bindTo($this),
-            \Closure::fromCallable([$this, 'evaluate'])->bindTo($this)
+            $this->compile(...)->bindTo($this),
+            $this->evaluate(...)->bindTo($this)
         );
     }
 
-    private function compile(string $codes, string $attribute, string $labels, string $locale, string $scope)
+    private function compile(string $codes, string $attribute, string $labels, string $locale, string $scope): string
     {
         return <<<PHP
             (function() {
                 \$linkedData = array_map(
                     function (string \$code) {
-                    \$labels = $labels;
-                    }
+                        static \$labels = {$labels};
+
                         return [
-                            'attribute' => $attribute,
+                            'attribute' => {$attribute},
                             'code' => \$code,
                             'labels' => \$labels[\$code] ?? [],
                         ];
                     },
-                    $codes,
+                    {$codes},
                 );
                 return [
                     [
-                        'data' => ($codes),
-                        'locale' => $locale,
-                        'scope' => $scope,
+                        'data' => ({$codes}),
+                        'locale' => {$locale},
+                        'scope' => {$scope},
                         'linked_data' => \$linkedData,
                     ],
                 ];
@@ -46,23 +46,20 @@ function (string \$code) {
     }
 
     /**
-     * @var list<string> $codes
-     * @var array<string, array<string, string>> $labels
+     * @return array<int, array<string, array|string|null>>
      */
-    private function evaluate(array $context, array $codes, string $attribute, array $labels, ?string $locale = null, ?string $scope = null)
+    private function evaluate(array $context, array $codes, string $attribute, array $labels, ?string $locale = null, ?string $scope = null): array
     {
         return [[
             'locale' => $locale,
             'scope' => $scope,
             'data' => $codes,
             'linked_data' => array_map(
-                function (string $code) use ($attribute, $labels) {
-                    return [
-                        'attribute' => $attribute,
-                        'code' => $code,
-                        'labels' => $labels[$code] ?? [],
-                    ];
-                },
+                fn (string $code) => [
+                    'attribute' => $attribute,
+                    'code' => $code,
+                    'labels' => $labels[$code] ?? [],
+                ],
                 $codes
             ),
         ]];
diff --git a/src/WithSimpleOption.php b/src/WithSimpleOption.php
index f8f29e4..35b37b0 100644
--- a/src/WithSimpleOption.php
+++ b/src/WithSimpleOption.php
@@ -12,23 +12,23 @@ public function __construct($name)
     {
         parent::__construct(
             $name,
-            \Closure::fromCallable([$this, 'compile'])->bindTo($this),
-            \Closure::fromCallable([$this, 'evaluate'])->bindTo($this)
+            $this->compile(...)->bindTo($this),
+            $this->evaluate(...)->bindTo($this)
         );
     }
 
-    private function compile(string $code, string $attribute, string $labels, string $locale = 'null', string $scope = 'null')
+    private function compile(string $code, string $attribute, string $labels, string $locale = 'null', string $scope = 'null'): string
     {
         return <<<PHP
             ([
                 [
-                    'data' => ($code),
-                    'locale' => $locale,
-                    'scope' => $scope,
+                    'data' => ({$code}),
+                    'locale' => {$locale},
+                    'scope' => {$scope},
                     'linked_data' => [
-                        'attribute' => ($attribute),
-                        'code' => ($code),
-                        'labels' => ($labels),
+                        'attribute' => ({$attribute}),
+                        'code' => ({$code}),
+                        'labels' => ({$labels}),
                     ],
                 ],
             ])
@@ -36,9 +36,9 @@ private function compile(string $code, string $attribute, string $labels, string
     }
 
     /**
-     * @var array<string, string> $labels
+     * @return array<int, array<string, array<string, array|string>|string|null>>
      */
-    private function evaluate(array $context, string $code, string $attribute, array $labels, ?string $locale = null, ?string $scope = null)
+    private function evaluate(array $context, string $code, string $attribute, array $labels, ?string $locale = null, ?string $scope = null): array
     {
         return [[
             'locale' => $locale,
diff --git a/src/WithValue.php b/src/WithValue.php
index f030f51..0f34b39 100644
--- a/src/WithValue.php
+++ b/src/WithValue.php
@@ -12,17 +12,17 @@ public function __construct($name)
     {
         parent::__construct(
             $name,
-            \Closure::fromCallable([$this, 'compile'])->bindTo($this),
-            \Closure::fromCallable([$this, 'evaluate'])->bindTo($this)
+            $this->compile(...)->bindTo($this),
+            $this->evaluate(...)->bindTo($this)
         );
     }
 
-    private function compile(string $value, string $locale = 'null', string $scope = 'null')
+    private function compile(string $value, string $locale = 'null', string $scope = 'null'): string
     {
         return sprintf('([["data" => (%s), "locale" => (%s), "scope" => (%s)]])', $value, $locale, $scope);
     }
 
-    private function evaluate(array $context, string $value, ?string $locale = null, ?string $scope = null)
+    private function evaluate(array $context, string $value, ?string $locale = null, ?string $scope = null): array
     {
         return [[
             'locale' => $locale,