diff --git a/src/HttpContentType.php b/src/HttpContentType.php
new file mode 100644
index 0000000..685a224
--- /dev/null
+++ b/src/HttpContentType.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace TinyBlocks\Http;
+
+use TinyBlocks\Http\Internal\Header;
+
+/**
+ * The Content-Type representation header is used to indicate the original media type
+ * of the resource (prior to any content encoding applied for sending).
+ *
+ * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type
+ */
+enum HttpContentType: string implements Header
+{
+    case TEXT_HTML = 'text/html';
+    case TEXT_PLAIN = 'text/plain';
+    case APPLICATION_PDF = 'application/pdf';
+    case APPLICATION_JSON = 'application/json';
+
+    public function key(): string
+    {
+        return 'Content-Type';
+    }
+
+    public function value(): string
+    {
+        return $this->value;
+    }
+}
diff --git a/src/HttpHeaders.php b/src/HttpHeaders.php
new file mode 100644
index 0000000..edf8b2f
--- /dev/null
+++ b/src/HttpHeaders.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace TinyBlocks\Http;
+
+use TinyBlocks\Http\Internal\Header;
+
+/**
+ * HTTP headers let the client and the server pass additional information with an HTTP request or response.
+ *
+ * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers
+ */
+final class HttpHeaders
+{
+    private array $values = [];
+
+    public function add(Header $header): HttpHeaders
+    {
+        $key = $header->key();
+        $this->values['header'][$key] = sprintf('%s: %s', $key, $header->value());
+
+        return $this;
+    }
+
+    public function getHeader(): array
+    {
+        return $this->values['header'] ?? [];
+    }
+
+    public function hasHeaders(): bool
+    {
+        return !empty($this->values);
+    }
+
+    public function hasHeader(string $key): bool
+    {
+        return !empty($this->getHeader()[$key]);
+    }
+
+    public function toArray(): array
+    {
+        return $this->values;
+    }
+}
diff --git a/src/HttpResponse.php b/src/HttpResponse.php
index c8c79e0..7c079f2 100644
--- a/src/HttpResponse.php
+++ b/src/HttpResponse.php
@@ -12,22 +12,22 @@
  */
 final class HttpResponse
 {
-    public static function ok(mixed $data, array $headers = []): ResponseInterface
+    public static function ok(mixed $data, ?HttpHeaders $headers = null): ResponseInterface
     {
         return Response::from(code: HttpCode::OK, data: $data, headers: $headers);
     }
 
-    public static function created(mixed $data, array $headers = []): ResponseInterface
+    public static function created(mixed $data, HttpHeaders $headers = null): ResponseInterface
     {
         return Response::from(code: HttpCode::CREATED, data: $data, headers: $headers);
     }
 
-    public static function accepted(mixed $data, array $headers = []): ResponseInterface
+    public static function accepted(mixed $data, HttpHeaders $headers = null): ResponseInterface
     {
         return Response::from(code: HttpCode::ACCEPTED, data: $data, headers: $headers);
     }
 
-    public static function noContent(array $headers = []): ResponseInterface
+    public static function noContent(HttpHeaders $headers = null): ResponseInterface
     {
         return Response::from(code: HttpCode::NO_CONTENT, data: null, headers: $headers);
     }
diff --git a/src/Internal/Header.php b/src/Internal/Header.php
new file mode 100644
index 0000000..6eb3807
--- /dev/null
+++ b/src/Internal/Header.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace TinyBlocks\Http\Internal;
+
+interface Header
+{
+    public function key(): string;
+
+    public function value(): string;
+}
diff --git a/src/Internal/Response.php b/src/Internal/Response.php
index 5cc31d0..999a4e0 100644
--- a/src/Internal/Response.php
+++ b/src/Internal/Response.php
@@ -6,6 +6,8 @@
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\StreamInterface;
 use TinyBlocks\Http\HttpCode;
+use TinyBlocks\Http\HttpContentType;
+use TinyBlocks\Http\HttpHeaders;
 use TinyBlocks\Http\Internal\Exceptions\BadMethodCall;
 use TinyBlocks\Http\Internal\Stream\StreamFactory;
 
@@ -14,14 +16,14 @@ final class Response implements ResponseInterface
     private function __construct(
         private readonly HttpCode $code,
         private readonly StreamInterface $body,
-        private readonly array $headers
+        private readonly HttpHeaders $headers
     ) {
     }
 
-    public static function from(HttpCode $code, mixed $data, array $headers): ResponseInterface
+    public static function from(HttpCode $code, mixed $data, ?HttpHeaders $headers): ResponseInterface
     {
-        if (empty($headers)) {
-            $headers[] = ['Content-Type' => 'application/json'];
+        if (is_null($headers) || !$headers->hasHeaders()) {
+            $headers = (new HttpHeaders())->add(header: HttpContentType::APPLICATION_JSON);
         }
 
         return new Response(code: $code, body: StreamFactory::from(data: $data), headers: $headers);
@@ -64,17 +66,17 @@ public function getProtocolVersion(): string
 
     public function getHeaders(): array
     {
-        return $this->headers;
+        return $this->headers->toArray();
     }
 
     public function hasHeader(string $name): bool
     {
-        return isset($this->headers[$name]);
+        return $this->headers->hasHeader(key: $name);
     }
 
     public function getHeader(string $name): array
     {
-        return $this->headers[$name] ?? [];
+        return $this->headers->getHeader();
     }
 
     public function getHeaderLine(string $name): string
diff --git a/tests/HttpResponseTest.php b/tests/HttpResponseTest.php
index dd01ab9..28c0399 100644
--- a/tests/HttpResponseTest.php
+++ b/tests/HttpResponseTest.php
@@ -8,7 +8,7 @@
 
 class HttpResponseTest extends TestCase
 {
-    private array $defaultHeader = [['Content-Type' => 'application/json']];
+    private array $defaultHeader = ['header' => ['Content-Type' => 'Content-Type: application/json']];
 
     /**
      * @dataProvider providerData
diff --git a/tests/Internal/HeadersTest.php b/tests/Internal/HeadersTest.php
new file mode 100644
index 0000000..8dcfb82
--- /dev/null
+++ b/tests/Internal/HeadersTest.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace TinyBlocks\Http\Internal;
+
+use PHPUnit\Framework\TestCase;
+use TinyBlocks\Http\HttpContentType;
+use TinyBlocks\Http\HttpHeaders;
+
+class HeadersTest extends TestCase
+{
+    public function testAddAndGetValues(): void
+    {
+        $headers = (new HttpHeaders())->add(header: HttpContentType::APPLICATION_JSON);
+        $expected = ['header' => ['Content-Type' => 'Content-Type: application/json']];
+
+        self::assertEquals($expected, $headers->toArray());
+    }
+
+    public function testAddAndGetUniqueValues(): void
+    {
+        $headers = (new HttpHeaders())
+            ->add(header: HttpContentType::TEXT_HTML)
+            ->add(header: HttpContentType::APPLICATION_PDF);
+
+        $expected = ['header' => ['Content-Type' => 'Content-Type: application/pdf']];
+
+        self::assertEquals($expected, $headers->toArray());
+    }
+}
diff --git a/tests/Internal/ResponseTest.php b/tests/Internal/ResponseTest.php
index 3f4d094..1ae43cc 100644
--- a/tests/Internal/ResponseTest.php
+++ b/tests/Internal/ResponseTest.php
@@ -4,125 +4,116 @@
 
 use PHPUnit\Framework\TestCase;
 use TinyBlocks\Http\HttpCode;
+use TinyBlocks\Http\HttpContentType;
+use TinyBlocks\Http\HttpHeaders;
 use TinyBlocks\Http\Internal\Exceptions\BadMethodCall;
 use TinyBlocks\Http\Internal\Stream\StreamFactory;
 
 class ResponseTest extends TestCase
 {
-    private Response $response;
+    private const TEXT_PLAIN = 'Content-Type: text/plain';
+    private const APPLICATION_JSON = 'Content-Type: application/json';
 
-    protected function setUp(): void
+    public function testDefaultHeaders(): void
     {
-        $this->response = Response::from(code: HttpCode::OK, data: [], headers: []);
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+        $expected = ['header' => ['Content-Type' => self::APPLICATION_JSON]];
+
+        self::assertEquals($expected, $response->getHeaders());
     }
 
     public function testGetProtocolVersion(): void
     {
-        self::assertEquals('1.1', $this->response->getProtocolVersion());
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+
+        self::assertEquals('1.1', $response->getProtocolVersion());
     }
 
     public function testGetHeaders(): void
     {
-        $headers = [
-            'Content-Type' => 'application/json',
-            'X-Auth-Token' => 'abc123'
-        ];
-
+        $headers = (new HttpHeaders())->add(header: HttpContentType::APPLICATION_JSON);
         $response = Response::from(code: HttpCode::OK, data: [], headers: $headers);
+        $expected = ['Content-Type' => self::APPLICATION_JSON];
 
-        self::assertEquals($headers, $response->getHeaders());
+        self::assertEquals($headers->toArray(), $response->getHeaders());
+        self::assertEquals($expected, $response->getHeader(name: 'Content-Type'));
     }
 
     public function testHasHeader(): void
     {
-        $headers = [
-            'Content-Type' => 'application/json',
-            'X-Auth-Token' => 'abc123'
-        ];
-
+        $headers = (new HttpHeaders())->add(header: HttpContentType::TEXT_PLAIN);
         $response = Response::from(code: HttpCode::OK, data: [], headers: $headers);
+        $expected = ['Content-Type' => self::TEXT_PLAIN];
 
         self::assertTrue($response->hasHeader(name: 'Content-Type'));
-        self::assertFalse($response->hasHeader(name: 'Authorization'));
-    }
-
-    public function testGetHeader(): void
-    {
-        $headers = [
-            'Content-Type'    => ['application/json'],
-            'X-Auth-Token'    => ['abc123'],
-            'X-Custom-Header' => ['value1', 'value2']
-        ];
-
-        $response = Response::from(code: HttpCode::OK, data: [], headers: $headers);
-
-        self::assertEquals(['application/json'], $response->getHeader(name: 'Content-Type'));
-        self::assertEquals(['abc123'], $response->getHeader(name: 'X-Auth-Token'));
-        self::assertEquals(['value1', 'value2'], $response->getHeader(name: 'X-Custom-Header'));
-        self::assertEquals([], $response->getHeader(name: 'Authorization'));
+        self::assertEquals($expected, $response->getHeader(name: 'Content-Type'));
     }
 
     public function testGetHeaderLine(): void
     {
-        $headers = [
-            'Content-Type'    => ['application/json'],
-            'X-Auth-Token'    => ['abc123'],
-            'X-Custom-Header' => ['value1', 'value2']
-        ];
-
+        $headers = (new HttpHeaders())->add(header: HttpContentType::APPLICATION_JSON);
         $response = Response::from(code: HttpCode::OK, data: [], headers: $headers);
 
-        self::assertEquals('application/json', $response->getHeaderLine(name: 'Content-Type'));
-        self::assertEquals('abc123', $response->getHeaderLine(name: 'X-Auth-Token'));
-        self::assertEquals('value1, value2', $response->getHeaderLine(name: 'X-Custom-Header'));
-        self::assertEquals('', $response->getHeaderLine(name: 'Authorization'));
+        self::assertEquals(self::APPLICATION_JSON, $response->getHeaderLine(name: 'Content-Type'));
     }
 
     public function testExceptionWhenBadMethodCallOnWithBody(): void
     {
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+
         self::expectException(BadMethodCall::class);
         self::expectExceptionMessage('Method <TinyBlocks\Http\Internal\Response::withBody> cannot be used.');
 
-        $this->response->withBody(body: StreamFactory::from(data: []));
+        $response->withBody(body: StreamFactory::from(data: []));
     }
 
     public function testExceptionWhenBadMethodCallOnWithStatus(): void
     {
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+
         self::expectException(BadMethodCall::class);
         self::expectExceptionMessage('Method <TinyBlocks\Http\Internal\Response::withStatus> cannot be used.');
 
-        $this->response->withStatus(code: HttpCode::OK->value);
+        $response->withStatus(code: HttpCode::OK->value);
     }
 
     public function testExceptionWhenBadMethodCallOnWithHeader(): void
     {
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+
         self::expectException(BadMethodCall::class);
         self::expectExceptionMessage('Method <TinyBlocks\Http\Internal\Response::withHeader> cannot be used.');
 
-        $this->response->withHeader(name: '', value: '');
+        $response->withHeader(name: '', value: '');
     }
 
     public function testExceptionWhenBadMethodCallOnWithoutHeader(): void
     {
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+
         self::expectException(BadMethodCall::class);
         self::expectExceptionMessage('Method <TinyBlocks\Http\Internal\Response::withoutHeader> cannot be used.');
 
-        $this->response->withoutHeader(name: '');
+        $response->withoutHeader(name: '');
     }
 
     public function testExceptionWhenBadMethodCallOnWithAddedHeader(): void
     {
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+
         self::expectException(BadMethodCall::class);
         self::expectExceptionMessage('Method <TinyBlocks\Http\Internal\Response::withAddedHeader> cannot be used.');
 
-        $this->response->withAddedHeader(name: '', value: '');
+        $response->withAddedHeader(name: '', value: '');
     }
 
     public function testExceptionWhenBadMethodCallOnWithProtocolVersion(): void
     {
+        $response = Response::from(code: HttpCode::OK, data: [], headers: null);
+
         self::expectException(BadMethodCall::class);
         self::expectExceptionMessage('Method <TinyBlocks\Http\Internal\Response::withProtocolVersion> cannot be used.');
 
-        $this->response->withProtocolVersion(version: '');
+        $response->withProtocolVersion(version: '');
     }
 }