diff --git a/tests/Composer/Test/Autoload/ClassLoaderTest.php b/tests/Composer/Test/Autoload/ClassLoaderTest.php
new file mode 100644
index 000000000..7a8ae253b
--- /dev/null
+++ b/tests/Composer/Test/Autoload/ClassLoaderTest.php
@@ -0,0 +1,65 @@
+<?php
+
+namespace Composer\Test\Autoload;
+
+use Composer\Autoload\ClassLoader;
+
+/**
+ * Tests the Composer\Autoload\ClassLoader class.
+ */
+class ClassLoaderTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * Tests regular PSR-0 and PSR-4 class loading.
+     *
+     * @dataProvider getLoadClassTests
+     *
+     * @param string $class
+     *   The fully-qualified class name to test,
+     *   without preceding namespace separator.
+     * @param bool $prependSeparator
+     *   Whether to call ->loadClass() with a class name with preceding
+     *   namespace separator, as it happens in PHP 5.3.0 - 5.3.2.
+     *   See https://bugs.php.net/50731
+     */
+    public function testLoadClass($class, $prependSeparator = FALSE)
+    {
+        $loader = new ClassLoader();
+        $loader->add('Namespaced\\', __DIR__ . '/Fixtures');
+        $loader->add('Pearlike_', __DIR__ . '/Fixtures');
+        $loader->addPsr4('ShinyVendor\\ShinyPackage\\', __DIR__ . '/Fixtures');
+
+        if ($prependSeparator) {
+          $prepend = '\\';
+          $message = "->loadClass() loads '$class'.";
+        }
+        else {
+          $prepend = '';
+          $message = "->loadClass() loads '\\$class', as required in PHP 5.3.0 - 5.3.2.";
+        }
+
+        $loader->loadClass($prepend . $class);
+        $this->assertTrue(class_exists($class, false), $message);
+    }
+
+    /**
+     * Provides arguments for ->testLoadClass().
+     *
+     * @return array
+     *   Array of parameter sets to test with.
+     */
+    public function getLoadClassTests()
+    {
+        return array(
+            array('Namespaced\\Foo'),
+            array('Pearlike_Foo'),
+            array('ShinyVendor\\ShinyPackage\\SubNamespace\\Foo'),
+            // "Bar" would not work here, since it is defined in a ".inc" file,
+            // instead of a ".php" file. So, use "Baz" instead.
+            array('Namespaced\\Baz', '\\'),
+            array('Pearlike_Bar', '\\'),
+            array('ShinyVendor\\ShinyPackage\\SubNamespace\\Bar', '\\'),
+        );
+    }
+
+}
diff --git a/tests/Composer/Test/Autoload/Fixtures/SubNamespace/Bar.php b/tests/Composer/Test/Autoload/Fixtures/SubNamespace/Bar.php
new file mode 100644
index 000000000..74cd9d7f3
--- /dev/null
+++ b/tests/Composer/Test/Autoload/Fixtures/SubNamespace/Bar.php
@@ -0,0 +1,5 @@
+<?php
+
+namespace ShinyVendor\ShinyPackage\SubNamespace;
+
+class Bar {}
diff --git a/tests/Composer/Test/Autoload/Fixtures/SubNamespace/Foo.php b/tests/Composer/Test/Autoload/Fixtures/SubNamespace/Foo.php
new file mode 100644
index 000000000..7406b732d
--- /dev/null
+++ b/tests/Composer/Test/Autoload/Fixtures/SubNamespace/Foo.php
@@ -0,0 +1,5 @@
+<?php
+
+namespace ShinyVendor\ShinyPackage\SubNamespace;
+
+class Foo {}