diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index ab3ca7ba..b2f91bc2 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -11,7 +11,7 @@ on:
 env:
   MIN_COVERED_MSI: 100
   MIN_MSI: 100
-  REQUIRED_PHP_EXTENSIONS: "mbstring"
+  REQUIRED_PHP_EXTENSIONS: "filter, mbstring"
 
 jobs:
   coding-standards:
diff --git a/.php_cs b/.php_cs
index 5aa11387..0727b5ca 100644
--- a/.php_cs
+++ b/.php_cs
@@ -13,16 +13,19 @@ declare(strict_types=1);
 
 use Ergebnis\PhpCsFixer\Config;
 
-$header = <<<'EOF'
-Copyright (c) 2019 Andreas Möller
-
+$header = Config\Header\Header::create(
+    Config\Header\CopyrightYears::fromYear(Config\Header\Year::fromString('2019')),
+    Config\Header\Author::fromString('Andreas Möller'),
+    Config\Header\License::fromString(
+        <<<'EOF'
 For the full copyright and license information, please view
 the LICENSE file that was distributed with this source code.
+EOF
+    ),
+    Config\Header\Url::fromString('https://github.com/ergebnis/php-cs-fixer-config')
+);
 
-@see https://github.com/ergebnis/php-cs-fixer-config
-EOF;
-
-$config = Config\Factory::fromRuleSet(new Config\RuleSet\Php71($header));
+$config = Config\Factory::fromRuleSet(new Config\RuleSet\Php71($header->toString()));
 
 $config->getFinder()
     ->ignoreDotFiles(false)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fe161c82..a5fb1601 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,10 @@ For a full diff see [`1.1.2...master`][1.1.2...master].
 
 For a full diff see [`1.1.1...1.1.2`][1.1.1...1.1.2].
 
+### Added
+
+* Allowed construction of header ([#23]), by [@localheinz]
+
 ### Fixed
 
 * Brought back support for PHP 7.1 ([#17]), by [@localheinz]
@@ -50,6 +54,7 @@ For a full diff see [`d899e77...1.0.0`][d899e77...1.0.0].
 [#3]: https://github.com/ergebnis/php-cs-fixer-config/pull/3
 [#14]: https://github.com/ergebnis/php-cs-fixer-config/pull/14
 [#17]: https://github.com/ergebnis/php-cs-fixer-config/pull/17
+[#23]: https://github.com/ergebnis/php-cs-fixer-config/pull/23
 
 [@linuxjuggler]: https://github.com/linuxjuggler
 [@localheinz]: https://github.com/localheinz
diff --git a/composer.json b/composer.json
index 45f5b9b7..581625de 100644
--- a/composer.json
+++ b/composer.json
@@ -12,6 +12,7 @@
   ],
   "require": {
     "php": "^7.1",
+    "ext-filter": "*",
     "friendsofphp/php-cs-fixer": "~2.16.0"
   },
   "require-dev": {
diff --git a/composer.lock b/composer.lock
index 10d4486f..ab4b93e7 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "0e22476b9fe63a75a739d6cbd9b6bc46",
+    "content-hash": "c89b5bca275f3a3fab9cbd570e300a16",
     "packages": [
         {
             "name": "composer/semver",
@@ -4814,7 +4814,8 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": "^7.1"
+        "php": "^7.1",
+        "ext-filter": "*"
     },
     "platform-dev": []
 }
diff --git a/src/Header/Author.php b/src/Header/Author.php
new file mode 100644
index 00000000..a52802a0
--- /dev/null
+++ b/src/Header/Author.php
@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Header;
+
+/**
+ * @internal
+ */
+final class Author
+{
+    private $value;
+
+    private function __construct(string $value)
+    {
+        $this->value = $value;
+    }
+
+    /**
+     * @param string $value
+     *
+     * @throws \InvalidArgumentException
+     *
+     * @return self
+     */
+    public static function fromString(string $value): self
+    {
+        $trimmed = \trim($value);
+
+        if ('' === $trimmed) {
+            throw new \InvalidArgumentException('Value cannot be blank or empty.');
+        }
+
+        return new self($trimmed);
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Header/CopyrightYears.php b/src/Header/CopyrightYears.php
new file mode 100644
index 00000000..009bab86
--- /dev/null
+++ b/src/Header/CopyrightYears.php
@@ -0,0 +1,66 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Header;
+
+/**
+ * @internal
+ */
+final class CopyrightYears
+{
+    private $value;
+
+    private function __construct(string $value)
+    {
+        $this->value = $value;
+    }
+
+    /**
+     * @param Year $startYear
+     * @param Year $endYear
+     *
+     * @throws \InvalidArgumentException
+     *
+     * @return self
+     */
+    public static function fromRange(Year $startYear, Year $endYear): self
+    {
+        if ($startYear->greaterThan($endYear)) {
+            throw new \InvalidArgumentException(\sprintf(
+                'Start year "%s" needs to be equal to or less than end year "%s".',
+                $startYear->toString(),
+                $endYear->toString()
+            ));
+        }
+
+        if ($startYear->equals($endYear)) {
+            return self::fromYear($startYear);
+        }
+
+        return new self(\sprintf(
+            '%s-%s',
+            $startYear->toString(),
+            $endYear->toString()
+        ));
+    }
+
+    public static function fromYear(Year $year): self
+    {
+        return new self($year->toString());
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Header/Header.php b/src/Header/Header.php
new file mode 100644
index 00000000..c7a9e2b4
--- /dev/null
+++ b/src/Header/Header.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Header;
+
+/**
+ * @internal
+ */
+final class Header
+{
+    private $copyrightYear;
+
+    private $author;
+
+    private $license;
+
+    private $url;
+
+    private function __construct(CopyrightYears $copyrightYear, Author $author, License $license, Url $url)
+    {
+        $this->copyrightYear = $copyrightYear;
+        $this->author = $author;
+        $this->license = $license;
+        $this->url = $url;
+    }
+
+    public static function create(CopyrightYears $copyrightYear, Author $author, License $license, Url $url): self
+    {
+        return new self(
+            $copyrightYear,
+            $author,
+            $license,
+            $url
+        );
+    }
+
+    public function toString(): string
+    {
+        if ($this->license->isEmpty()) {
+            return <<<EOF
+Copyright (c) {$this->copyrightYear->toString()} {$this->author->toString()}
+
+@see {$this->url->toString()}
+EOF;
+        }
+
+        return <<<EOF
+Copyright (c) {$this->copyrightYear->toString()} {$this->author->toString()}
+
+{$this->license->toString()}
+
+@see {$this->url->toString()}
+EOF;
+    }
+}
diff --git a/src/Header/License.php b/src/Header/License.php
new file mode 100644
index 00000000..5363ca14
--- /dev/null
+++ b/src/Header/License.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Header;
+
+/**
+ * @internal
+ */
+final class License
+{
+    private $value;
+
+    private function __construct(string $value)
+    {
+        $this->value = $value;
+    }
+
+    public static function fromString(string $value): self
+    {
+        return new self(\trim($value));
+    }
+
+    public function isEmpty(): bool
+    {
+        return '' === $this->value;
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Header/Url.php b/src/Header/Url.php
new file mode 100644
index 00000000..ecd61eee
--- /dev/null
+++ b/src/Header/Url.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Header;
+
+/**
+ * @internal
+ */
+final class Url
+{
+    private $value;
+
+    private function __construct(string $value)
+    {
+        $this->value = $value;
+    }
+
+    /**
+     * @param string $value
+     *
+     * @throws \InvalidArgumentException
+     *
+     * @return self
+     */
+    public static function fromString(string $value): self
+    {
+        $trimmed = \trim($value);
+
+        if (false === \filter_var($trimmed, \FILTER_VALIDATE_URL)) {
+            throw new \InvalidArgumentException(\sprintf(
+                'Value "%s" does not appear to be a valid URL.',
+                $value
+            ));
+        }
+
+        return new self($trimmed);
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Header/Year.php b/src/Header/Year.php
new file mode 100644
index 00000000..c03c8e74
--- /dev/null
+++ b/src/Header/Year.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Header;
+
+/**
+ * @internal
+ */
+final class Year
+{
+    private $value;
+
+    private function __construct(string $value)
+    {
+        $this->value = $value;
+    }
+
+    /**
+     * @param string $value
+     *
+     * @throws \InvalidArgumentException
+     *
+     * @return self
+     */
+    public static function fromString(string $value): self
+    {
+        if (1 !== \preg_match('/^\d{4}$/', $value)) {
+            throw new \InvalidArgumentException(\sprintf(
+                'Value "%s" does not appear to be a valid year.',
+                $value
+            ));
+        }
+
+        return new self($value);
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+
+    public function equals(self $other): bool
+    {
+        return $this->value === $other->value;
+    }
+
+    public function greaterThan(self $other): bool
+    {
+        return $this->value > $other->value;
+    }
+}
diff --git a/test/Unit/Header/AuthorTest.php b/test/Unit/Header/AuthorTest.php
new file mode 100644
index 00000000..8e13de27
--- /dev/null
+++ b/test/Unit/Header/AuthorTest.php
@@ -0,0 +1,110 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Test\Unit\Header;
+
+use Ergebnis\PhpCsFixer\Config\Header\Author;
+use Ergebnis\Test\Util\Helper;
+use PHPUnit\Framework;
+
+/**
+ * @internal
+ *
+ * @covers \Ergebnis\PhpCsFixer\Config\Header\Author
+ */
+final class AuthorTest extends Framework\TestCase
+{
+    use Helper;
+
+    /**
+     * @dataProvider provideInvalidValue
+     *
+     * @param string $value
+     */
+    public function testFromStringRejectsInvalidValue(string $value): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Value cannot be blank or empty.');
+
+        Author::fromString($value);
+    }
+
+    public function provideInvalidValue(): \Generator
+    {
+        $values = [
+            'string-blank' => '  ',
+            'string-empty' => '',
+        ];
+
+        foreach ($values as $key => $value) {
+            yield $key => [
+                $value,
+            ];
+        }
+    }
+
+    /**
+     * @dataProvider provideValidValue
+     *
+     * @param string $value
+     */
+    public function testFromStringReturnsAuthor(string $value): void
+    {
+        $author = Author::fromString($value);
+
+        self::assertSame($value, $author->toString());
+    }
+
+    public function provideValidValue(): \Generator
+    {
+        foreach (self::validValues() as $key => $value) {
+            yield $key => [
+                $value,
+            ];
+        }
+    }
+
+    /**
+     * @dataProvider provideUntrimmedValue
+     *
+     * @param string $value
+     */
+    public function testFromStringReturnsAuthorWithTrimmedValue(string $value): void
+    {
+        $author = Author::fromString($value);
+
+        self::assertSame(\trim($value), $author->toString());
+    }
+
+    public function provideUntrimmedValue(): \Generator
+    {
+        foreach (self::validValues() as $key => $value) {
+            yield $key => [
+                \sprintf(
+                    " %s \n\n",
+                    $value
+                ),
+            ];
+        }
+    }
+
+    private static function validValues(): array
+    {
+        return [
+            'string-first-name' => 'Andreas',
+            'string-full-name' => 'Andreas Möller',
+            'string-handle' => 'localheinz',
+            'string-last-name' => 'Möller',
+        ];
+    }
+}
diff --git a/test/Unit/Header/CopyrightYearsTest.php b/test/Unit/Header/CopyrightYearsTest.php
new file mode 100644
index 00000000..df8bd36b
--- /dev/null
+++ b/test/Unit/Header/CopyrightYearsTest.php
@@ -0,0 +1,92 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Test\Unit\Header;
+
+use Ergebnis\PhpCsFixer\Config\Header\CopyrightYears;
+use Ergebnis\PhpCsFixer\Config\Header\Year;
+use Ergebnis\Test\Util\Helper;
+use PHPUnit\Framework;
+
+/**
+ * @internal
+ *
+ * @covers \Ergebnis\PhpCsFixer\Config\Header\CopyrightYears
+ *
+ * @uses \Ergebnis\PhpCsFixer\Config\Header\Year
+ * @uses \Ergebnis\PhpCsFixer\Config\Header\Author
+ * @uses \Ergebnis\PhpCsFixer\Config\Header\Url
+ */
+final class CopyrightYearsTest extends Framework\TestCase
+{
+    use Helper;
+
+    public function testFromRangeRequiresStartYearToBeEqualOrLessThanEndYear(): void
+    {
+        $startYear = Year::fromString('2020');
+        $endYear = Year::fromString('2019');
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage(\sprintf(
+            'Start year "%s" needs to be equal to or less than end year "%s".',
+            $startYear->toString(),
+            $endYear->toString()
+        ));
+
+        CopyrightYears::fromRange(
+            $startYear,
+            $endYear
+        );
+    }
+
+    public function testFromRangeReturnsCopyrightYearsWhenStartYearEqualsEndYear(): void
+    {
+        $startYear = Year::fromString('2020');
+        $endYear = Year::fromString('2020');
+
+        $copyrightYears = CopyrightYears::fromRange(
+            $startYear,
+            $endYear
+        );
+
+        self::assertSame($startYear->toString(), $copyrightYears->toString());
+    }
+
+    public function testFromRangeReturnsCopyrightYearsWhenStartYearIsLessThanEndYear(): void
+    {
+        $startYear = Year::fromString('2019');
+        $endYear = Year::fromString('2020');
+
+        $copyrightYears = CopyrightYears::fromRange(
+            $startYear,
+            $endYear
+        );
+
+        $expected = \sprintf(
+            '%s-%s',
+            $startYear->toString(),
+            $endYear->toString()
+        );
+
+        self::assertSame($expected, $copyrightYears->toString());
+    }
+
+    public function testFromYearReturnsCopyrightYears(): void
+    {
+        $year = Year::fromString('2019');
+
+        $copyrightYears = CopyrightYears::fromYear($year);
+
+        self::assertSame($year->toString(), $copyrightYears->toString());
+    }
+}
diff --git a/test/Unit/Header/HeaderTest.php b/test/Unit/Header/HeaderTest.php
new file mode 100644
index 00000000..dcf6226a
--- /dev/null
+++ b/test/Unit/Header/HeaderTest.php
@@ -0,0 +1,105 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Test\Unit\Header;
+
+use Ergebnis\PhpCsFixer\Config\Header\Author;
+use Ergebnis\PhpCsFixer\Config\Header\CopyrightYears;
+use Ergebnis\PhpCsFixer\Config\Header\Header;
+use Ergebnis\PhpCsFixer\Config\Header\License;
+use Ergebnis\PhpCsFixer\Config\Header\Url;
+use Ergebnis\PhpCsFixer\Config\Header\Year;
+use Ergebnis\Test\Util\Helper;
+use PHPUnit\Framework;
+
+/**
+ * @internal
+ *
+ * @covers \Ergebnis\PhpCsFixer\Config\Header\Header
+ *
+ * @uses \Ergebnis\PhpCsFixer\Config\Header\CopyrightYears
+ * @uses \Ergebnis\PhpCsFixer\Config\Header\Year
+ * @uses \Ergebnis\PhpCsFixer\Config\Header\Author
+ * @uses \Ergebnis\PhpCsFixer\Config\Header\Url
+ */
+final class HeaderTest extends Framework\TestCase
+{
+    use Helper;
+
+    public function testCreateReturnsHeaderWhenLicenseIsEmpty(): void
+    {
+        $faker = self::faker();
+
+        $copyrightYears = CopyrightYears::fromRange(
+            Year::fromString('2019'),
+            Year::fromString(\date('2020'))
+        );
+
+        $author = Author::fromString($faker->name);
+
+        $url = Url::fromString($faker->url);
+
+        $header = Header::create(
+            $copyrightYears,
+            $author,
+            License::fromString(''),
+            $url
+        );
+
+        $expected = <<<EOF
+Copyright (c) {$copyrightYears->toString()} {$author->toString()}
+
+@see {$url->toString()}
+EOF;
+
+        self::assertSame($expected, $header->toString());
+    }
+
+    public function testCreateReturnsHeaderWhenLicenseIsNotEmpty(): void
+    {
+        $faker = self::faker();
+
+        $copyrightYears = CopyrightYears::fromRange(
+            Year::fromString('2019'),
+            Year::fromString(\date('2020'))
+        );
+
+        $author = Author::fromString($faker->name);
+
+        $license = License::fromString(
+            <<<'EOF'
+For the full copyright and license information, please view
+the LICENSE file that was distributed with this source code.
+EOF
+        );
+
+        $url = Url::fromString($faker->url);
+
+        $header = Header::create(
+            $copyrightYears,
+            $author,
+            $license,
+            $url
+        );
+
+        $expected = <<<EOF
+Copyright (c) {$copyrightYears->toString()} {$author->toString()}
+
+{$license->toString()}
+
+@see {$url->toString()}
+EOF;
+
+        self::assertSame($expected, $header->toString());
+    }
+}
diff --git a/test/Unit/Header/LicenseTest.php b/test/Unit/Header/LicenseTest.php
new file mode 100644
index 00000000..92bd68cc
--- /dev/null
+++ b/test/Unit/Header/LicenseTest.php
@@ -0,0 +1,81 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Test\Unit\Header;
+
+use Ergebnis\PhpCsFixer\Config\Header\License;
+use Ergebnis\Test\Util\Helper;
+use PHPUnit\Framework;
+
+/**
+ * @internal
+ *
+ * @covers \Ergebnis\PhpCsFixer\Config\Header\License
+ */
+final class LicenseTest extends Framework\TestCase
+{
+    use Helper;
+
+    /**
+     * @dataProvider provideValidValue
+     *
+     * @param string $value
+     */
+    public function testFromStringReturnsLicense(string $value): void
+    {
+        $license = License::fromString($value);
+
+        self::assertSame($value, $license->toString());
+    }
+
+    public function provideValidValue(): \Generator
+    {
+        foreach (self::validValues() as $key => $value) {
+            yield $key => [
+                $value,
+            ];
+        }
+    }
+
+    /**
+     * @dataProvider provideUntrimmedValue
+     *
+     * @param string $value
+     */
+    public function testFromStringReturnsLicenseWithTrimmedValue(string $value): void
+    {
+        $license = License::fromString($value);
+
+        self::assertSame(\trim($value), $license->toString());
+    }
+
+    public function provideUntrimmedValue(): \Generator
+    {
+        foreach (self::validValues() as $key => $value) {
+            yield $key => [
+                \sprintf(
+                    " %s \n\n",
+                    $value
+                ),
+            ];
+        }
+    }
+
+    private static function validValues(): array
+    {
+        return [
+            'string-arbitrary' => self::faker()->realText(),
+            'string-empty' => '',
+        ];
+    }
+}
diff --git a/test/Unit/Header/UrlTest.php b/test/Unit/Header/UrlTest.php
new file mode 100644
index 00000000..8404c294
--- /dev/null
+++ b/test/Unit/Header/UrlTest.php
@@ -0,0 +1,112 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Test\Unit\Header;
+
+use Ergebnis\PhpCsFixer\Config\Header\Url;
+use Ergebnis\Test\Util\Helper;
+use PHPUnit\Framework;
+
+/**
+ * @internal
+ *
+ * @covers \Ergebnis\PhpCsFixer\Config\Header\Url
+ */
+final class UrlTest extends Framework\TestCase
+{
+    use Helper;
+
+    /**
+     * @dataProvider provideInvalidValue
+     *
+     * @param string $value
+     */
+    public function testFromStringRejectsInvalidValue(string $value): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage(\sprintf(
+            'Value "%s" does not appear to be a valid URL.',
+            $value
+        ));
+
+        Url::fromString($value);
+    }
+
+    public function provideInvalidValue(): \Generator
+    {
+        $values = [
+            'string-arbitrary' => self::faker()->sentence,
+            'string-blank' => '  ',
+            'string-empty' => '',
+        ];
+
+        foreach ($values as $key => $value) {
+            yield $key => [
+                $value,
+            ];
+        }
+    }
+
+    /**
+     * @dataProvider provideValidValue
+     *
+     * @param string $value
+     */
+    public function testFromStringReturnsUrl(string $value): void
+    {
+        $url = Url::fromString($value);
+
+        self::assertSame($value, $url->toString());
+    }
+
+    public function provideValidValue(): \Generator
+    {
+        foreach (self::validValues() as $key => $value) {
+            yield $key => [
+                $value,
+            ];
+        }
+    }
+
+    /**
+     * @dataProvider provideUntrimmedValue
+     *
+     * @param string $value
+     */
+    public function testFromStringReturnsUrlWithTrimmedValue(string $value): void
+    {
+        $author = Url::fromString($value);
+
+        self::assertSame(\trim($value), $author->toString());
+    }
+
+    public function provideUntrimmedValue(): \Generator
+    {
+        foreach (self::validValues() as $key => $value) {
+            yield $key => [
+                \sprintf(
+                    " %s \n\n",
+                    $value
+                ),
+            ];
+        }
+    }
+
+    private static function validValues(): array
+    {
+        return [
+            'string-https' => 'https://github.com/ergebnis/php-cs-fixer-config',
+            'string-http' => 'http://github.com/ergebnis/php-cs-fixer-config',
+        ];
+    }
+}
diff --git a/test/Unit/Header/YearTest.php b/test/Unit/Header/YearTest.php
new file mode 100644
index 00000000..e0abe259
--- /dev/null
+++ b/test/Unit/Header/YearTest.php
@@ -0,0 +1,138 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright (c) 2019 Andreas Möller
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ *
+ * @see https://github.com/ergebnis/php-cs-fixer-config
+ */
+
+namespace Ergebnis\PhpCsFixer\Config\Test\Unit\Header;
+
+use Ergebnis\PhpCsFixer\Config\Header\Year;
+use Ergebnis\Test\Util\Helper;
+use PHPUnit\Framework;
+
+/**
+ * @internal
+ *
+ * @covers \Ergebnis\PhpCsFixer\Config\Header\Year
+ */
+final class YearTest extends Framework\TestCase
+{
+    use Helper;
+
+    /**
+     * @dataProvider provideInvalidValue
+     *
+     * @param string $value
+     */
+    public function testFromStringRejectsInvalidValue(string $value): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage(\sprintf(
+            'Value "%s" does not appear to be a valid year.',
+            $value
+        ));
+
+        Year::fromString($value);
+    }
+
+    public function provideInvalidValue(): \Generator
+    {
+        $faker = self::faker();
+
+        $values = [
+            'string-arbitrary' => $faker->sentence,
+            'string-blank' => '  ',
+            'string-containing-year' => \sprintf(
+                '%s %s %s',
+                $faker->word,
+                \date('Y'),
+                $faker->word
+            ),
+            'string-empty' => '',
+        ];
+
+        foreach ($values as $key => $value) {
+            yield $key => [
+                $value,
+            ];
+        }
+    }
+
+    /**
+     * @dataProvider provideValidValue
+     *
+     * @param string $value
+     */
+    public function testFromStringReturnsYear(string $value): void
+    {
+        $year = Year::fromString($value);
+
+        self::assertSame($value, $year->toString());
+    }
+
+    public function provideValidValue(): \Generator
+    {
+        $values = [
+            'string-end' => '0000',
+            'string-start' => '9999',
+            'string-today' => \date('Y'),
+        ];
+
+        foreach ($values as $key => $value) {
+            yield $key => [
+                $value,
+            ];
+        }
+    }
+
+    public function testEqualsReturnsFalseWhenValueIsDifferent(): void
+    {
+        $one = Year::fromString('2020');
+        $two = Year::fromString('2021');
+
+        self::assertFalse($one->equals($two));
+    }
+
+    public function testEqualsReturnsTrueWhenValueIsSame(): void
+    {
+        $value = '2020';
+
+        $one = Year::fromString($value);
+        $two = Year::fromString($value);
+
+        self::assertTrue($one->equals($two));
+    }
+
+    public function testGreaterThanReturnsFalseWhenValueIsEqual(): void
+    {
+        $value = '2020';
+
+        $one = Year::fromString($value);
+        $two = Year::fromString($value);
+
+        self::assertFalse($one->greaterThan($two));
+    }
+
+    public function testGreaterThanReturnsFalseWhenValueIsLess(): void
+    {
+        $one = Year::fromString('2019');
+        $two = Year::fromString('2020');
+
+        self::assertFalse($one->greaterThan($two));
+    }
+
+    public function testGreaterThanReturnsTrueWhenValueIsGreater(): void
+    {
+        $one = Year::fromString('2020');
+        $two = Year::fromString('2019');
+
+        self::assertTrue($one->greaterThan($two));
+    }
+}