diff --git a/libraries/loader.php b/libraries/loader.php
index af3d01df45840..ac5b1100f9dde 100644
--- a/libraries/loader.php
+++ b/libraries/loader.php
@@ -62,7 +62,7 @@ abstract class JLoader
 	 * @var    array
 	 * @since  12.3
 	 */
-	protected static $namespaces = array('psr0' => array(), 'psr4' => array());
+	protected static $namespaces = array('psr4' => array());
 
 	/**
 	 * Holds a reference for all deprecated aliases (mainly for use by a logging platform).
@@ -158,11 +158,11 @@ public static function getDeprecatedAliases()
 	 *
 	 * @since   12.3
 	 */
-	public static function getNamespaces($type = 'psr0')
+	public static function getNamespaces($type = 'psr4')
 	{
-		if ($type !== 'psr0' && $type !== 'psr4')
+		if ($type !== 'psr4')
 		{
-			throw new InvalidArgumentException('Type needs to be prs0 or psr4!');
+			throw new InvalidArgumentException('Type needs to be psr4!');
 		}
 
 		return self::$namespaces[$type];
@@ -397,14 +397,13 @@ public static function registerAlias($alias, $original, $version = false)
 	 *
 	 * @throws  RuntimeException
 	 *
-	 * @note    The default argument of $type will be changed in J4 to be 'psr4'
 	 * @since   12.3
 	 */
-	public static function registerNamespace($namespace, $path, $reset = false, $prepend = false, $type = 'psr0')
+	public static function registerNamespace($namespace, $path, $reset = false, $prepend = false, $type = 'psr4')
 	{
-		if ($type !== 'psr0' && $type !== 'psr4')
+		if ($type !== 'psr4')
 		{
-			throw new InvalidArgumentException('Type needs to be prs0 or psr4!');
+			throw new InvalidArgumentException('Type needs to be psr4!');
 		}
 
 		// Verify the library path exists.
@@ -470,7 +469,6 @@ public static function setup($enablePsr = true, $enablePrefixes = true, $enableC
 		if ($enablePsr)
 		{
 			// Register the PSR-0 based autoloader.
-			spl_autoload_register(array('JLoader', 'loadByPsr0'));
 			spl_autoload_register(array('JLoader', 'loadByPsr4'));
 			spl_autoload_register(array('JLoader', 'loadByAlias'));
 		}
@@ -535,65 +533,6 @@ public static function loadByPsr4($class)
 		return false;
 	}
 
-	/**
-	 * Method to autoload classes that are namespaced to the PSR-0 standard.
-	 *
-	 * @param   string  $class  The fully qualified class name to autoload.
-	 *
-	 * @return  boolean  True on success, false otherwise.
-	 *
-	 * @since   13.1
-	 *
-	 * @deprecated 4.0 this method will be removed
-	 */
-	public static function loadByPsr0($class)
-	{
-		// Remove the root backslash if present.
-		if ($class[0] == '\\')
-		{
-			$class = substr($class, 1);
-		}
-
-		// Find the location of the last NS separator.
-		$pos = strrpos($class, '\\');
-
-		// If one is found, we're dealing with a NS'd class.
-		if ($pos !== false)
-		{
-			$classPath = str_replace('\\', DIRECTORY_SEPARATOR, substr($class, 0, $pos)) . DIRECTORY_SEPARATOR;
-			$className = substr($class, $pos + 1);
-		}
-		// If not, no need to parse path.
-		else
-		{
-			$classPath = null;
-			$className = $class;
-		}
-
-		$classPath .= str_replace('_', DIRECTORY_SEPARATOR, $className) . '.php';
-
-		// Loop through registered namespaces until we find a match.
-		foreach (self::$namespaces['psr0'] as $ns => $paths)
-		{
-			if (strpos($class, $ns) === 0)
-			{
-				// Loop through paths registered to this namespace until we find a match.
-				foreach ($paths as $path)
-				{
-					$classFilePath = $path . DIRECTORY_SEPARATOR . $classPath;
-
-					// We check for class_exists to handle case-sensitive file systems
-					if (file_exists($classFilePath) && !class_exists($class, false))
-					{
-						return (bool) include_once $classFilePath;
-					}
-				}
-			}
-		}
-
-		return false;
-	}
-
 	/**
 	 * Method to autoload classes that have been aliased using the registerAlias method.
 	 *
diff --git a/tests/unit/suites/libraries/joomla/JLoaderTest.php b/tests/unit/suites/libraries/joomla/JLoaderTest.php
index ec75701e4aaa5..cf9c242aaafbb 100644
--- a/tests/unit/suites/libraries/joomla/JLoaderTest.php
+++ b/tests/unit/suites/libraries/joomla/JLoaderTest.php
@@ -516,7 +516,7 @@ public function testSetupDefaultParameters()
 
 		$foundLoad = false;
 		$foundAutoload = false;
-		$foundLoadByPsr0 = false;
+		$foundLoadByPsr4 = false;
 		$foundLoadByAlias = false;
 
 		// We search the list of autoload functions to see if our methods are there.
@@ -534,9 +534,9 @@ public function testSetupDefaultParameters()
 					$foundAutoload = true;
 				}
 
-				if ($loader[1] === 'loadByPsr0')
+				if ($loader[1] === 'loadByPsr4')
 				{
-					$foundLoadByPsr0 = true;
+					$foundLoadByPsr4 = true;
 				}
 
 				if ($loader[1] === 'loadByAlias')
@@ -557,7 +557,7 @@ public function testSetupDefaultParameters()
 		$this->assertTrue($foundAutoload);
 
 		// Assert the PSR-0 loader is found.
-		$this->assertTrue($foundLoadByPsr0);
+		$this->assertTrue($foundLoadByPsr4);
 
 		// Assert the Alias loader is found.
 		$this->assertTrue($foundLoadByAlias);
@@ -661,7 +661,7 @@ public function testSetupPsr0()
 		// Get the autoload functions
 		$loaders = spl_autoload_functions();
 
-		$foundLoadPsr0 = false;
+		$foundLoadPsr4 = false;
 		$foundLoadAlias = false;
 
 		// We search the list of autoload functions to see if our method is here.
@@ -669,7 +669,7 @@ public function testSetupPsr0()
 		{
 			if (is_array($loader) && $loader[0] === 'JLoader')
 			{
-				if ($loader[1] === 'loadByPsr0')
+				if ($loader[1] === 'loadByPsr4')
 				{
 					$foundLoadPsr0 = true;
 				}
@@ -706,7 +706,7 @@ protected function unregisterLoaders()
 			if (is_array($loader) && $loader[0] === 'JLoader'
 				&& ($loader[1] === 'load'
 				|| $loader[1] === '_autoload'
-				|| $loader[1] === 'loadByPsr0'
+				|| $loader[1] === 'loadByPsr4'
 				|| $loader[1] === 'loadByAlias'))
 			{
 				spl_autoload_unregister($loader);