diff --git a/src/Dto/AbstractDto.php b/src/Dto/AbstractDto.php
index b641153..4892e27 100644
--- a/src/Dto/AbstractDto.php
+++ b/src/Dto/AbstractDto.php
@@ -4,6 +4,7 @@
 
 namespace PhpCollective\Dto\Dto;
 
+use PhpCollective\Dto\Transformer\TransformerRegistry;
 use PhpCollective\Dto\Utility\Json;
 use RuntimeException;
 
@@ -18,7 +19,7 @@ abstract class AbstractDto extends Dto
      */
     public function fromArray(array $data, bool $ignoreMissing = false, ?string $type = null): static
     {
-        if ($type === null && static::HAS_FAST_PATH) {
+        if ($type === null && static::HAS_FAST_PATH && !TransformerRegistry::hasAnyCaster()) {
             if (!$ignoreMissing) {
                 $this->validateFieldNames($data);
             }
diff --git a/src/Dto/Dto.php b/src/Dto/Dto.php
index 3cbefbf..a74f7bf 100644
--- a/src/Dto/Dto.php
+++ b/src/Dto/Dto.php
@@ -274,7 +274,7 @@ public static function create(?array $data = null, bool $ignoreMissing = false,
     public function __construct(?array $data = null, bool $ignoreMissing = false, ?string $type = null)
     {
         if ($data) {
-            if ($type === null && static::HAS_FAST_PATH && !TransformerRegistry::hasAny()) {
+            if ($type === null && static::HAS_FAST_PATH && !TransformerRegistry::hasAnyCaster()) {
                 if (!$ignoreMissing) {
                     $this->validateFieldNames($data);
                 }
@@ -340,7 +340,7 @@ protected function _toArrayInternal(?string $type = null, ?array $fields = null,
         if (
             !$touched && $fields === null && static::HAS_FAST_PATH
             && ($type === null || $type === static::TYPE_CAMEL || $type === static::TYPE_DEFAULT)
-            && !TransformerRegistry::hasAny()
+            && !TransformerRegistry::hasAnySerializer()
         ) {
             return $this->toArrayFast();
         }
diff --git a/src/Transformer/TransformerRegistry.php b/src/Transformer/TransformerRegistry.php
index 31dc043..0db60dc 100644
--- a/src/Transformer/TransformerRegistry.php
+++ b/src/Transformer/TransformerRegistry.php
@@ -174,6 +174,28 @@ public static function hasAny(): bool
         return self::$casters !== [] || self::$serializers !== [];
     }
 
+    /**
+     * Check whether any caster is currently registered.
+     * Used to bypass generated fast paths on input (hydration).
+     *
+     * @return bool
+     */
+    public static function hasAnyCaster(): bool
+    {
+        return self::$casters !== [];
+    }
+
+    /**
+     * Check whether any serializer is currently registered.
+     * Used to bypass generated fast paths on output (serialization).
+     *
+     * @return bool
+     */
+    public static function hasAnySerializer(): bool
+    {
+        return self::$serializers !== [];
+    }
+
     /**
      * @param string $type
      *
diff --git a/tests/Dto/DtoTest.php b/tests/Dto/DtoTest.php
index fd6e5fa..7368a05 100644
--- a/tests/Dto/DtoTest.php
+++ b/tests/Dto/DtoTest.php
@@ -19,6 +19,7 @@
 use PhpCollective\Dto\Test\TestDto\AssociativeCollectionDto;
 use PhpCollective\Dto\Test\TestDto\CollectionDto;
 use PhpCollective\Dto\Test\TestDto\CustomCollectionDto;
+use PhpCollective\Dto\Test\TestDto\FastPathCasterDto;
 use PhpCollective\Dto\Test\TestDto\ImmutableCollectionDto;
 use PhpCollective\Dto\Test\TestDto\ImmutableDto;
 use PhpCollective\Dto\Test\TestDto\MapFromDto;
@@ -1755,6 +1756,60 @@ public function testMultipleRequiredFieldsErrorMessageFormat(): void
         }
     }
 
+    public function testGlobalCasterAppliesToClassFieldOnFastPathFromArray(): void
+    {
+        TransformerRegistry::addCaster(
+            PlainClass::class,
+            fn (mixed $value): PlainClass => new PlainClass('cast:' . (string)$value),
+        );
+
+        $dto = (new FastPathCasterDto())->fromArray(['plainData' => 'hello']);
+
+        $plain = $dto->getPlainData();
+        $this->assertInstanceOf(PlainClass::class, $plain);
+        $this->assertSame('cast:hello', $plain->value);
+    }
+
+    public function testGlobalCasterAppliesToClassFieldOnFastPathConstructor(): void
+    {
+        TransformerRegistry::addCaster(
+            PlainClass::class,
+            fn (mixed $value): PlainClass => new PlainClass('cast:' . (string)$value),
+        );
+
+        $dto = new FastPathCasterDto(['plainData' => 'hello']);
+
+        $plain = $dto->getPlainData();
+        $this->assertInstanceOf(PlainClass::class, $plain);
+        $this->assertSame('cast:hello', $plain->value);
+    }
+
+    public function testGlobalSerializerAppliesToFastPathToArray(): void
+    {
+        TransformerRegistry::addSerializer(
+            PlainClass::class,
+            fn (PlainClass $value): string => 'serialized:' . $value->value,
+        );
+
+        $dto = (new FastPathCasterDto())->setPlainData(new PlainClass('abc'));
+
+        $this->assertSame(['plainData' => 'serialized:abc'], $dto->toArray());
+    }
+
+    public function testGlobalSerializerDoesNotDisableFastPathHydration(): void
+    {
+        TransformerRegistry::addSerializer(
+            PlainClass::class,
+            fn (PlainClass $value): string => 'serialized:' . $value->value,
+        );
+
+        $dto = (new FastPathCasterDto())->fromArray(['plainData' => 'hello']);
+
+        $plain = $dto->getPlainData();
+        $this->assertInstanceOf(PlainClass::class, $plain);
+        $this->assertSame('hello', $plain->value);
+    }
+
     public function testGlobalCasterAppliesToClassField(): void
     {
         TransformerRegistry::addCaster(
diff --git a/tests/TestDto/FastPathCasterDto.php b/tests/TestDto/FastPathCasterDto.php
new file mode 100644
index 0000000..ba6a5b5
--- /dev/null
+++ b/tests/TestDto/FastPathCasterDto.php
@@ -0,0 +1,122 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpCollective\Dto\Test\TestDto;
+
+use PhpCollective\Dto\Dto\AbstractDto;
+use PhpCollective\Dto\Test\Generator\Fixtures\PlainClass;
+
+/**
+ * Mimics generated output for a DTO with a class-typed field and fast-path methods.
+ */
+class FastPathCasterDto extends AbstractDto
+{
+    /**
+     * @var bool
+     */
+    protected const HAS_FAST_PATH = true;
+
+    protected ?PlainClass $plainData = null;
+
+    /**
+     * @var array<string, array<string, mixed>>
+     */
+    protected array $_metadata = [
+        'plainData' => [
+            'type' => PlainClass::class,
+            'required' => false,
+            'defaultValue' => null,
+            'dto' => false,
+            'collectionType' => null,
+            'singularType' => null,
+            'associative' => false,
+            'key' => null,
+            'serialize' => null,
+            'factory' => null,
+            'isClass' => true,
+            'enum' => null,
+        ],
+    ];
+
+    /**
+     * @var array<string, array<string, string>>
+     */
+    protected array $_keyMap = [
+        'underscored' => [
+            'plain_data' => 'plainData',
+        ],
+        'dashed' => [
+            'plain-data' => 'plainData',
+        ],
+    ];
+
+    public function getPlainData(): ?PlainClass
+    {
+        return $this->plainData;
+    }
+
+    public function setPlainData(?PlainClass $plainData): self
+    {
+        $this->plainData = $plainData;
+        $this->_touchedFields['plainData'] = true;
+
+        return $this;
+    }
+
+    public function hasPlainData(): bool
+    {
+        return $this->plainData !== null;
+    }
+
+    /**
+     * @param array<string, mixed> $data
+     *
+     * @return void
+     */
+    protected function setFromArrayFast(array $data): void
+    {
+        if (isset($data['plainData'])) {
+            $value = $data['plainData'];
+            if (!$value instanceof PlainClass) {
+                $value = new PlainClass($value);
+            }
+            $this->plainData = $value;
+            $this->_touchedFields['plainData'] = true;
+        }
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    protected function toArrayFast(): array
+    {
+        return [
+            'plainData' => $this->plainData !== null ? $this->plainData->value : null,
+        ];
+    }
+
+    /**
+     * @param string|null $type
+     * @param array<string>|null $fields
+     * @param bool $touched
+     *
+     * @return array<string, mixed>
+     */
+    public function toArray(?string $type = null, ?array $fields = null, bool $touched = false): array
+    {
+        return $this->_toArrayInternal($type, $fields, $touched);
+    }
+
+    /**
+     * @param array<string, mixed> $data
+     * @param bool $ignoreMissing
+     * @param string|null $type
+     *
+     * @return static
+     */
+    public static function createFromArray(array $data, bool $ignoreMissing = false, ?string $type = null): static
+    {
+        return static::_createFromArrayInternal($data, $ignoreMissing, $type);
+    }
+}