diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
index c68ff75..406a498 100644
--- a/.github/workflows/php.yml
+++ b/.github/workflows/php.yml
@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        php_version: ['8.1', '8.2', '8.3']
+        php_version: ['8.1', '8.2', '8.3', '8.4']
         laravel_version: ['^9.0', '^10.0', '^11.0']
         exclude:
           - php_version: '8.1'
diff --git a/CHANGELOG-1.4.md b/CHANGELOG-1.4.md
index bcc63a2..4ffc537 100644
--- a/CHANGELOG-1.4.md
+++ b/CHANGELOG-1.4.md
@@ -1,10 +1,20 @@
 Release note
 ============
-# v1.4.4
+# v1.4.6
+### Change
+- Support PHP 8.4
+### Fixed
+- Fix `applyWhen` behavior
+
+# v1.4.5
 ### Change
 - `applyWhen` condition can be a closure
 - CI: test all supported laravel version
 
+# v1.4.4
+### Fixes
+- typo on ToResponse : change Content-type to Content-Type
+
 # v1.4.3
 ### Added
 - Add support for Laravel 11
diff --git a/phpunit.php8.4.xml.dist b/phpunit.php8.4.xml.dist
new file mode 100644
index 0000000..8ef7a48
--- /dev/null
+++ b/phpunit.php8.4.xml.dist
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.5/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         executionOrder="depends,defects"
+         failOnRisky="true"
+         failOnWarning="true"
+>
+  <testsuites>
+    <testsuite name="Unit">
+      <directory>tests/Unit</directory>
+    </testsuite>
+    <testsuite name="Feature">
+      <directory>tests/Feature</directory>
+    </testsuite>
+  </testsuites>
+  <php>
+    <env name="DB_CONNECTION" value="sqlite"/>
+    <env name="DB_DATABASE" value=":memory:"/>
+  </php>
+  <source>
+    <include>
+      <directory suffix=".php">src</directory>
+    </include>
+  </source>
+</phpunit>
diff --git a/src/Asserts/AssertJsonApiResource.php b/src/Asserts/AssertJsonApiResource.php
new file mode 100644
index 0000000..6bc1182
--- /dev/null
+++ b/src/Asserts/AssertJsonApiResource.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace Ark4ne\JsonApi\Asserts;
+
+use Ark4ne\JsonApi\Descriptors\Values\Value;
+use Ark4ne\JsonApi\Resources\JsonApiResource;
+use Ark4ne\JsonApi\Support\FakeModel;
+use Ark4ne\JsonApi\Support\Values;
+use Illuminate\Http\Request;
+use Illuminate\Http\Resources\MissingValue;
+use ReflectionClass;
+
+class AssertJsonApiResource
+{
+    /**
+     * @param class-string<JsonApiResource> $class
+     */
+    public function __construct(protected string $class)
+    {
+    }
+
+    public function assert(): void
+    {
+        $this->itCanGenerateSchema();
+        $this->allAttributesAreLazySet();
+    }
+
+    private function itCanGenerateSchema(): void
+    {
+        try {
+            $this->class::schema();
+        } catch (\Throwable $throwable) {
+            throw new FailGenerateSchema($this->class, $throwable);
+        }
+    }
+
+    private function allAttributesAreLazySet(): void
+    {
+        $reflection = new ReflectionClass($this->class);
+        $instance = $reflection->newInstanceWithoutConstructor();
+        $instance->resource = new FakeModel;
+
+        $method = $reflection->getMethod('toAttributes');
+        $method->setAccessible(true);
+        /** @var iterable<array-key, mixed> $attributes */
+        $attributes = $method->invoke($instance, new Request());
+        $attributes = Values::mergeValues($attributes);
+
+        foreach ($attributes as $key => $attribute) {
+            if (!($attribute instanceof \Closure || $attribute instanceof MissingValue || $attribute instanceof Value)) {
+                throw new EagerSetAttribute($this->class, $key);
+            }
+        }
+    }
+}
diff --git a/src/Asserts/EagerSetAttribute.php b/src/Asserts/EagerSetAttribute.php
new file mode 100644
index 0000000..b3b854d
--- /dev/null
+++ b/src/Asserts/EagerSetAttribute.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Ark4ne\JsonApi\Asserts;
+
+use Throwable;
+
+class EagerSetAttribute extends \Exception
+{
+    public function __construct(string $class, string $key, ?Throwable $previous = null)
+    {
+        parent::__construct("Attribute [$key] on resource [$class] is eager set.", 0, $previous);
+    }
+}
diff --git a/src/Asserts/FailGenerateSchema.php b/src/Asserts/FailGenerateSchema.php
new file mode 100644
index 0000000..8c9f724
--- /dev/null
+++ b/src/Asserts/FailGenerateSchema.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Ark4ne\JsonApi\Asserts;
+
+use Throwable;
+
+class FailGenerateSchema extends \Exception
+{
+    public function __construct(string $class, ?Throwable $previous = null)
+    {
+        parent::__construct("Can't generate schema for resource [$class].", 0, $previous);
+    }
+}
diff --git a/src/Descriptors/Relations/Relation.php b/src/Descriptors/Relations/Relation.php
index ac141a6..46a3f83 100644
--- a/src/Descriptors/Relations/Relation.php
+++ b/src/Descriptors/Relations/Relation.php
@@ -65,7 +65,7 @@ public function meta(Closure $meta): static
      * @param bool|null $whenIncluded
      * @return $this
      */
-    public function whenIncluded(bool $whenIncluded = null): static
+    public function whenIncluded(null|bool $whenIncluded = null): static
     {
         if ($whenIncluded === null) {
             $this->whenIncluded ??= true;
@@ -83,7 +83,7 @@ public function whenIncluded(bool $whenIncluded = null): static
      *
      * @return static
      */
-    public function whenLoaded(string $relation = null): self
+    public function whenLoaded(null|string $relation = null): self
     {
         return $this->when(fn(
             Request $request,
@@ -100,7 +100,7 @@ public function whenLoaded(string $relation = null): self
      *
      * @return static
      */
-    public function whenPivotLoaded(string $table, string $accessor = null): self
+    public function whenPivotLoaded(string $table, null|string $accessor = null): self
     {
         return $this->when(fn(
             Request $request,
diff --git a/src/Descriptors/Values/ValueRaw.php b/src/Descriptors/Values/ValueRaw.php
deleted file mode 100644
index db0aa72..0000000
--- a/src/Descriptors/Values/ValueRaw.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-namespace Ark4ne\JsonApi\Descriptors\Values;
-
-use Closure;
-
-/**
- * @internal
- * @template T
- * @extends Value<T>
- */
-class ValueRaw extends Value
-{
-    public function __construct(
-        null|string|Closure $attribute,
-        protected mixed $raw
-    ) {
-        parent::__construct($attribute);
-    }
-
-    public function value(mixed $of): mixed
-    {
-        return $this->raw;
-    }
-}
diff --git a/src/Resources/Concerns/ConditionallyLoadsAttributes.php b/src/Resources/Concerns/ConditionallyLoadsAttributes.php
index a6cd0d7..feb1d1a 100644
--- a/src/Resources/Concerns/ConditionallyLoadsAttributes.php
+++ b/src/Resources/Concerns/ConditionallyLoadsAttributes.php
@@ -4,7 +4,7 @@
 
 use Ark4ne\JsonApi\Descriptors\Describer;
 use Ark4ne\JsonApi\Descriptors\Relations\RelationRaw;
-use Ark4ne\JsonApi\Descriptors\Values\ValueRaw;
+use Ark4ne\JsonApi\Descriptors\Values\ValueMixed;
 use Ark4ne\JsonApi\Resources\Relationship;
 use Ark4ne\JsonApi\Support\Fields;
 use Ark4ne\JsonApi\Support\Includes;
@@ -57,13 +57,13 @@ protected function whenIncluded(Request $request, string $type, mixed $value)
      */
     protected function applyWhen(bool|Closure $condition, iterable $data): MergeValue
     {
-        return new MergeValue(collect($data)->map(function ($raw, $key) use ($condition) {
+        return new MergeValue(collect($data)->map(function ($raw) use ($condition) {
             if ($raw instanceof Describer) {
                 $value = $raw;
             } elseif ($raw instanceof Relationship) {
                 $value = RelationRaw::fromRelationship($raw);
             } else {
-                $value = new ValueRaw($key, $raw);
+                $value = new ValueMixed(is_callable($raw) ? $raw : static fn () => $raw);
             }
 
             return $value->when(fn () => value($condition));
diff --git a/src/Resources/Concerns/Relationships.php b/src/Resources/Concerns/Relationships.php
index abd97f1..131f9c0 100644
--- a/src/Resources/Concerns/Relationships.php
+++ b/src/Resources/Concerns/Relationships.php
@@ -60,7 +60,7 @@ private function requestedRelationshipsLoadFromSchema(Request $request, Skeleton
             if ($load && Includes::include($request, $name)) {
                 $include = Includes::through($name, fn() => $this->requestedRelationshipsLoadFromSchema($request, $schema->relationships[$name]));
 
-                $apply = static function ($load, string $pre = null) use (&$loads, &$apply) {
+                $apply = static function ($load, null|string $pre = null) use (&$loads, &$apply) {
                     foreach ((array)$load as $key => $value) {
                         if (is_string($value)) {
                             $loads["$pre.$value"] = [];
diff --git a/src/Resources/Concerns/Schema.php b/src/Resources/Concerns/Schema.php
index 4e593e4..8499bd8 100644
--- a/src/Resources/Concerns/Schema.php
+++ b/src/Resources/Concerns/Schema.php
@@ -21,7 +21,7 @@ trait Schema
      */
     private static array $schemas = [];
 
-    public static function schema(Request $request = null): Skeleton
+    public static function schema(null|Request $request = null): Skeleton
     {
         if (isset(self::$schemas[static::class])) {
             return self::$schemas[static::class];
diff --git a/src/Resources/Concerns/SchemaCollection.php b/src/Resources/Concerns/SchemaCollection.php
index dedfbb3..39f314d 100644
--- a/src/Resources/Concerns/SchemaCollection.php
+++ b/src/Resources/Concerns/SchemaCollection.php
@@ -8,7 +8,7 @@
 
 trait SchemaCollection
 {
-    public static function schema(Request $request = null): Skeleton
+    public static function schema(null|Request $request = null): Skeleton
     {
         return self::new()->collects::schema($request);
     }
diff --git a/src/Resources/Relationship.php b/src/Resources/Relationship.php
index 6083e38..c8a64c9 100644
--- a/src/Resources/Relationship.php
+++ b/src/Resources/Relationship.php
@@ -100,7 +100,7 @@ public function asCollection(): self
      * @param bool|null $whenIncluded
      * @return $this
      */
-    public function whenIncluded(bool $whenIncluded = null): static
+    public function whenIncluded(null|bool $whenIncluded = null): static
     {
         if ($whenIncluded === null) {
             $this->whenIncluded ??= true;
diff --git a/src/Support/Arr.php b/src/Support/Arr.php
index 3aae71d..f83b64e 100644
--- a/src/Support/Arr.php
+++ b/src/Support/Arr.php
@@ -107,7 +107,7 @@ private static function flattenDot(array $array, string $prepend, string $saveKe
      * @param string|null $saveKey
      * @return array<mixed>
      */
-    public static function undot(array $array, string $saveKey = null): array
+    public static function undot(array $array, null|string $saveKey = null): array
     {
         $results = [];
 
@@ -129,7 +129,7 @@ public static function undot(array $array, string $saveKey = null): array
      * @param string|null $saveKey
      * @return mixed
      */
-    public static function apply(array &$array, string $path, mixed $value, string $saveKey = null): mixed
+    public static function apply(array &$array, string $path, mixed $value, null|string $saveKey = null): mixed
     {
         $keys = explode('.', $path);
 
diff --git a/src/Support/Fields.php b/src/Support/Fields.php
index 0020b35..c17cf59 100644
--- a/src/Support/Fields.php
+++ b/src/Support/Fields.php
@@ -37,7 +37,7 @@ public static function through(string $type, callable $callable): mixed
      *
      * @return string[]|null
      */
-    public static function get(Request $request, string $type = null): ?array
+    public static function get(Request $request, null|string $type = null): ?array
     {
         $type ??= self::$current;
 
@@ -57,7 +57,7 @@ public static function get(Request $request, string $type = null): ?array
      *
      * @return bool
      */
-    public static function has(Request $request, string $field, string $type =null): bool  {
+    public static function has(Request $request, string $field, null|string $type =null): bool  {
         $type ??= self::$current;
 
         if ($type === null) {
diff --git a/tests/Feature/SchemaTest.php b/tests/Feature/SchemaTest.php
index 8a3b147..4978272 100644
--- a/tests/Feature/SchemaTest.php
+++ b/tests/Feature/SchemaTest.php
@@ -13,7 +13,14 @@ class SchemaTest extends FeatureTestCase
 {
     public function testSchema()
     {
-        $user = new Skeleton(UserResource::class, 'user', ['name', 'email', 'only-with-fields']);
+        $user = new Skeleton(UserResource::class, 'user', [
+            'name',
+            'email',
+            'only-with-fields',
+            'with-apply-conditional-raw',
+            'with-apply-conditional-closure',
+            'with-apply-conditional-value',
+        ]);
         $post = new Skeleton(PostResource::class, 'post', ['state', 'title', 'content']);
         $comment = new Skeleton(CommentResource::class, 'comment', ['content']);
 
diff --git a/tests/Feature/User/ResourceTest.php b/tests/Feature/User/ResourceTest.php
index 20c67c3..c1ab1c5 100644
--- a/tests/Feature/User/ResourceTest.php
+++ b/tests/Feature/User/ResourceTest.php
@@ -164,7 +164,16 @@ private function getJsonResult(User $user, ?array $attributes = null, ?array $re
                 'attributes' => array_filter(array_intersect_key([
                     'name' => $user->name,
                     'email' => $user->email,
-                ], array_fill_keys($attributes ?? ['name', 'email'], true))),
+                    "with-apply-conditional-closure" => "huge-data-set",
+                    "with-apply-conditional-raw" => "huge-data-set",
+                    "with-apply-conditional-value" => "huge-data-set"
+                ], array_fill_keys($attributes ?? [
+                    'name',
+                    'email',
+                    "with-apply-conditional-closure",
+                    "with-apply-conditional-raw",
+                    "with-apply-conditional-value",
+                ], true))),
                 'relationships' => [
                     'main-post' => [],
                     'posts' => array_filter([
diff --git a/tests/Unit/Resources/Concerns/ConditionallyLoadsAttributesTest.php b/tests/Unit/Resources/Concerns/ConditionallyLoadsAttributesTest.php
index d9b4dcb..4af60e2 100644
--- a/tests/Unit/Resources/Concerns/ConditionallyLoadsAttributesTest.php
+++ b/tests/Unit/Resources/Concerns/ConditionallyLoadsAttributesTest.php
@@ -7,6 +7,7 @@
 use Ark4ne\JsonApi\Descriptors\Values\ValueMixed;
 use Ark4ne\JsonApi\Descriptors\Values\ValueRaw;
 use Ark4ne\JsonApi\Resources\Concerns\ConditionallyLoadsAttributes;
+use Ark4ne\JsonApi\Resources\JsonApiResource;
 use Ark4ne\JsonApi\Resources\Relationship;
 use Illuminate\Http\Request;
 use Illuminate\Http\Resources\Json\JsonResource;
@@ -75,16 +76,16 @@ public function testApplyWhen()
             'missing.2' => 123,
         ]);
         $this->assertEquals(new MergeValue([
-            'missing.1' => (new ValueRaw('missing.1', 'abc'))->when(fn () => false),
-            'missing.2' => (new ValueRaw('missing.2', 123))->when(fn () => false),
+            'missing.1' => (new ValueMixed(fn() => 'abc'))->when(fn() => false),
+            'missing.2' => (new ValueMixed(fn() => 123))->when(fn() => false),
         ]), $actual);
         $actual = Reflect::invoke($stub, 'applyWhen', true, [
             'present.1' => 'abc',
             'present.2' => 123,
         ]);
         $this->assertEquals(new MergeValue([
-            'present.1' => (new ValueRaw('present.1', 'abc'))->when(fn () => true),
-            'present.2' => (new ValueRaw('present.2', 123))->when(fn () => true),
+            'present.1' => (new ValueMixed(fn() => 'abc'))->when(fn() => true),
+            'present.2' => (new ValueMixed(fn() => 123))->when(fn() => true),
         ]), $actual);
         $actual = Reflect::invoke($stub, 'applyWhen', true, [
             'present.1' => (new ValueMixed(fn() => 'abc')),
@@ -94,11 +95,11 @@ public function testApplyWhen()
             'present.5' => (new Relationship(UserResource::class, fn() => null)),
         ]);
         $this->assertEquals(new MergeValue([
-            'present.1' => (new ValueMixed(fn() => 'abc'))->when(fn () => true),
-            'present.2' => (new ValueMixed(fn() => 123))->when(fn () => true),
-            'present.3' => (new RelationOne('present', fn() => 'abc'))->when(fn () => true),
-            'present.4' => (new RelationOne('present', fn() => 123))->when(fn () => true),
-            'present.5' => RelationRaw::fromRelationship(new Relationship(UserResource::class, fn() => null))->when(fn () => true),
+            'present.1' => (new ValueMixed(fn() => 'abc'))->when(fn() => true),
+            'present.2' => (new ValueMixed(fn() => 123))->when(fn() => true),
+            'present.3' => (new RelationOne('present', fn() => 'abc'))->when(fn() => true),
+            'present.4' => (new RelationOne('present', fn() => 123))->when(fn() => true),
+            'present.5' => RelationRaw::fromRelationship(new Relationship(UserResource::class, fn() => null))->when(fn() => true),
         ]), $actual);
         $actual = Reflect::invoke($stub, 'applyWhen', false, [
             'missing.1' => (new ValueMixed(fn() => 'abc')),
@@ -108,11 +109,11 @@ public function testApplyWhen()
             'missing.5' => (new Relationship(UserResource::class, fn() => null)),
         ]);
         $this->assertEquals(new MergeValue([
-            'missing.1' => (new ValueMixed(fn() => 'abc'))->when(fn () => false),
-            'missing.2' => (new ValueMixed(fn() => 123))->when(fn () => false),
-            'missing.3' => (new RelationOne('present', fn() => 'abc'))->when(fn () => false),
-            'missing.4' => (new RelationOne('present', fn() => 123))->when(fn () => false),
-            'missing.5' => RelationRaw::fromRelationship(new Relationship(UserResource::class, fn() => null))->when(fn () => false),
+            'missing.1' => (new ValueMixed(fn() => 'abc'))->when(fn() => false),
+            'missing.2' => (new ValueMixed(fn() => 123))->when(fn() => false),
+            'missing.3' => (new RelationOne('present', fn() => 'abc'))->when(fn() => false),
+            'missing.4' => (new RelationOne('present', fn() => 123))->when(fn() => false),
+            'missing.5' => RelationRaw::fromRelationship(new Relationship(UserResource::class, fn() => null))->when(fn() => false),
         ]), $actual);
     }
 
diff --git a/tests/app/Http/Resources/UserResource.php b/tests/app/Http/Resources/UserResource.php
index 47e0d66..47ae055 100644
--- a/tests/app/Http/Resources/UserResource.php
+++ b/tests/app/Http/Resources/UserResource.php
@@ -25,6 +25,11 @@ protected function toAttributes(Request $request): iterable
             'name' => $this->resource->name,
             'email' => $this->resource->email,
             'only-with-fields' => $this->string(fn() => 'huge-data-set')->whenInFields(),
+            $this->applyWhen(fn () => true, [
+                'with-apply-conditional-raw' => 'huge-data-set',
+                'with-apply-conditional-closure' => fn () => 'huge-data-set',
+                'with-apply-conditional-value' => $this->string(fn () => 'huge-data-set'),
+            ]),
         ];
     }