diff --git a/src/Uri.php b/src/Uri.php
index 122ab01..490d691 100644
--- a/src/Uri.php
+++ b/src/Uri.php
@@ -126,7 +126,7 @@ public function __construct(string $uri)
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 *
 	 * @link https://tools.ietf.org/html/rfc3986#section-3.1
 	 */
@@ -136,10 +136,10 @@ public function setScheme(string $scheme) : UriInterface
 
 		if (! \preg_match($regex, $scheme))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "scheme"');
+			throw new UriException('Invalid URI component "scheme"');
 		}
 
-		$this->scheme = $scheme;
+		$this->scheme = \strtolower($scheme);
 
 		return $this;
 	}
@@ -147,7 +147,7 @@ public function setScheme(string $scheme) : UriInterface
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 *
 	 * @link https://tools.ietf.org/html/rfc3986#section-3.2.1
 	 */
@@ -157,7 +157,7 @@ public function setUsername(string $username) : UriInterface
 
 		if (! \preg_match($regex, $username))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "username"');
+			throw new UriException('Invalid URI component "username"');
 		}
 
 		$this->username = $username;
@@ -168,7 +168,7 @@ public function setUsername(string $username) : UriInterface
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 *
 	 * @link https://tools.ietf.org/html/rfc3986#section-3.2.1
 	 */
@@ -178,7 +178,7 @@ public function setPassword(string $password) : UriInterface
 
 		if (! \preg_match($regex, $password))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "password"');
+			throw new UriException('Invalid URI component "password"');
 		}
 
 		$this->password = $password;
@@ -189,7 +189,7 @@ public function setPassword(string $password) : UriInterface
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 *
 	 * @link https://tools.ietf.org/html/rfc3986#section-3.2.2
 	 */
@@ -199,10 +199,10 @@ public function setHost(string $host) : UriInterface
 
 		if (! \preg_match($regex, $host))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "host"');
+			throw new UriException('Invalid URI component "host"');
 		}
 
-		$this->host = $host;
+		$this->host = \strtolower($host);
 
 		return $this;
 	}
@@ -210,7 +210,7 @@ public function setHost(string $host) : UriInterface
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 */
 	public function setPort(?int $port) : UriInterface
 	{
@@ -219,7 +219,7 @@ public function setPort(?int $port) : UriInterface
 
 		if (! ($port === null || ($port >= $min && $port <= $max)))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "port"');
+			throw new UriException('Invalid URI component "port"');
 		}
 
 		$this->port = $port;
@@ -230,7 +230,7 @@ public function setPort(?int $port) : UriInterface
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 *
 	 * @link https://tools.ietf.org/html/rfc3986#section-3.3
 	 */
@@ -240,7 +240,7 @@ public function setPath(string $path) : UriInterface
 
 		if (! \preg_match($regex, $path))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "path"');
+			throw new UriException('Invalid URI component "path"');
 		}
 
 		$this->path = $path;
@@ -251,7 +251,7 @@ public function setPath(string $path) : UriInterface
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 *
 	 * @link https://tools.ietf.org/html/rfc3986#section-3.4
 	 */
@@ -261,7 +261,7 @@ public function setQuery(string $query) : UriInterface
 
 		if (! \preg_match($regex, $query))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "query"');
+			throw new UriException('Invalid URI component "query"');
 		}
 
 		$this->query = $query;
@@ -272,7 +272,7 @@ public function setQuery(string $query) : UriInterface
 	/**
 	 * {@inheritDoc}
 	 *
-	 * @throws \InvalidArgumentException
+	 * @throws \Sunrise\Uri\UriException
 	 *
 	 * @link https://tools.ietf.org/html/rfc3986#section-3.5
 	 */
@@ -282,7 +282,7 @@ public function setFragment(string $fragment) : UriInterface
 
 		if (! \preg_match($regex, $fragment))
 		{
-			throw new \InvalidArgumentException('Invalid URI component "fragment"');
+			throw new UriException('Invalid URI component "fragment"');
 		}
 
 		$this->fragment = $fragment;
diff --git a/src/UriException.php b/src/UriException.php
new file mode 100644
index 0000000..d1c6e52
--- /dev/null
+++ b/src/UriException.php
@@ -0,0 +1,25 @@
+<?php declare(strict_types=1);
+
+/**
+ * It's free open-source software released under the MIT License.
+ *
+ * @author Anatoly Fenric <anatoly@fenric.ru>
+ * @copyright Copyright (c) 2018, Anatoly Fenric
+ * @license https://github.com/sunrise-php/uri/blob/master/LICENSE
+ * @link https://github.com/sunrise-php/uri
+ */
+
+namespace Sunrise\Uri;
+
+/**
+ * Import classes
+ */
+use RuntimeException;
+
+/**
+ * UriException
+ *
+ * @package Sunrise\Uri
+ */
+class UriException extends RuntimeException
+{}
diff --git a/tests/UriTest.php b/tests/UriTest.php
index fc99836..62b5972 100644
--- a/tests/UriTest.php
+++ b/tests/UriTest.php
@@ -3,11 +3,11 @@
 namespace Sunrise\Uri\Tests;
 
 use PHPUnit\Framework\TestCase;
-use Sunrise\Uri\{Uri, UriInterface};
+use Sunrise\Uri\{Uri, UriException, UriInterface};
 
 class UriTest extends TestCase
 {
-	public const TEST_URI = 'scheme://username:password@localhost:8080/path?query#fragment';
+	public const TEST_URI = 'scheme://username:password@localhost:3000/path?query#fragment';
 
 	// Constructor...
 
@@ -52,7 +52,7 @@ public function testGetPort()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$this->assertEquals(8080, $uri->getPort());
+		$this->assertEquals(3000, $uri->getPort());
 	}
 
 	public function testGetPath()
@@ -82,72 +82,72 @@ public function testSetScheme()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setScheme('redefinedScheme');
+		$uri->setScheme('new-scheme');
 
-		$this->assertEquals('redefinedScheme', $uri->getScheme());
+		$this->assertEquals('new-scheme', $uri->getScheme());
 	}
 
 	public function testSetUsername()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setUsername('redefinedUsername');
+		$uri->setUsername('new-username');
 
-		$this->assertEquals('redefinedUsername', $uri->getUsername());
+		$this->assertEquals('new-username', $uri->getUsername());
 	}
 
 	public function testSetPassword()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setPassword('redefinedPassword');
+		$uri->setPassword('new-password');
 
-		$this->assertEquals('redefinedPassword', $uri->getPassword());
+		$this->assertEquals('new-password', $uri->getPassword());
 	}
 
 	public function testSetHost()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setHost('redefinedHost');
+		$uri->setHost('new-host');
 
-		$this->assertEquals('redefinedHost', $uri->getHost());
+		$this->assertEquals('new-host', $uri->getHost());
 	}
 
 	public function testSetPort()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setPort(666);
+		$uri->setPort(80);
 
-		$this->assertEquals(666, $uri->getPort());
+		$this->assertEquals(80, $uri->getPort());
 	}
 
 	public function testSetPath()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setPath('/redefinedPath');
+		$uri->setPath('/new-path');
 
-		$this->assertEquals('/redefinedPath', $uri->getPath());
+		$this->assertEquals('/new-path', $uri->getPath());
 	}
 
 	public function testSetQuery()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setQuery('redefinedQuery');
+		$uri->setQuery('new-query');
 
-		$this->assertEquals('redefinedQuery', $uri->getQuery());
+		$this->assertEquals('new-query', $uri->getQuery());
 	}
 
 	public function testSetFragment()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setFragment('redefinedFragment');
+		$uri->setFragment('new-fragment');
 
-		$this->assertEquals('redefinedFragment', $uri->getFragment());
+		$this->assertEquals('new-fragment', $uri->getFragment());
 	}
 
 	// Setters with empty data...
@@ -228,43 +228,43 @@ public function testSetEmptyFragment()
 
 	public function testSetInvalidScheme()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setScheme(':invalidScheme:');
+		$uri->setScheme('scheme://');
 	}
 
 	public function testSetInvalidUsername()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setUsername(':invalidUsername:');
+		$uri->setUsername('username:password');
 	}
 
 	public function testSetInvalidPassword()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setPassword(':invalidPassword:');
+		$uri->setPassword('username:password:');
 	}
 
 	public function testSetInvalidHost()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setHost(':invalidHost:');
+		$uri->setHost('localhost:80');
 	}
 
 	public function testSetInvalidPortWhichIsLessThanZero()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
@@ -273,7 +273,7 @@ public function testSetInvalidPortWhichIsLessThanZero()
 
 	public function testSetInvalidPortWhichIsZero()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
@@ -282,7 +282,7 @@ public function testSetInvalidPortWhichIsZero()
 
 	public function testSetInvalidPortWhichIsGreaterThanTheMaximum()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
@@ -291,29 +291,29 @@ public function testSetInvalidPortWhichIsGreaterThanTheMaximum()
 
 	public function testSetInvalidPath()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setPath('?invalidPath?');
+		$uri->setPath('/path?query');
 	}
 
 	public function testSetInvalidQuery()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setQuery('#invalidQuery#');
+		$uri->setQuery('query#fragment');
 	}
 
 	public function testSetInvalidFragment()
 	{
-		$this->expectException(\InvalidArgumentException::class);
+		$this->expectException(UriException::class);
 
 		$uri = new Uri(self::TEST_URI);
 
-		$uri->setFragment('#invalidFragment#');
+		$uri->setFragment('fragment#another-fragment');
 	}
 
 	// Builds...
@@ -329,14 +329,14 @@ public function testBuildHostPort()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$this->assertEquals('localhost:8080', $uri->getHostPort());
+		$this->assertEquals('localhost:3000', $uri->getHostPort());
 	}
 
 	public function testBuildAuthority()
 	{
 		$uri = new Uri(self::TEST_URI);
 
-		$this->assertEquals('username:password@localhost:8080', $uri->getAuthority());
+		$this->assertEquals('username:password@localhost:3000', $uri->getAuthority());
 	}
 
 	public function testBuildFullUri()
@@ -345,4 +345,24 @@ public function testBuildFullUri()
 
 		$this->assertEquals(self::TEST_URI, $uri->toString());
 	}
+
+	// Normalizes...
+
+	public function testNormalizeSchemeToLowerCase()
+	{
+		$uri = new Uri(self::TEST_URI);
+
+		$uri->setScheme('SCHEME');
+
+		$this->assertEquals('scheme', $uri->getScheme());
+	}
+
+	public function testNormalizeHostToLowerCase()
+	{
+		$uri = new Uri(self::TEST_URI);
+
+		$uri->setHost('LOCALHOST');
+
+		$this->assertEquals('localhost', $uri->getHost());
+	}
 }