diff --git a/lib/autoloader.php b/lib/autoloader.php
index 9cc573c099..215da536e5 100644
--- a/lib/autoloader.php
+++ b/lib/autoloader.php
@@ -94,7 +94,7 @@ class Autoloader {
 			$paths[] = \OC::$CLASSPATH[$class];
 			/**
 			 * @TODO: Remove this when necessary
-			 * Remove "apps/" from inclusion path for smooth migration to mutli app dir
+			 * Remove "apps/" from inclusion path for smooth migration to multi app dir
 			 */
 			if (strpos(\OC::$CLASSPATH[$class], 'apps/') === 0) {
 				\OCP\Util::writeLog('core', 'include path for class "' . $class . '" starts with "apps/"', \OCP\Util::DEBUG);
@@ -113,8 +113,10 @@ class Autoloader {
 				// If not found in the root of the app directory, insert '/lib' after app id and try again.
 				$paths[] = $appPath . '/lib/' . strtolower(str_replace('\\', '/', $rest) . '.php');
 			}
-		} elseif (strpos($class, 'Test_') === 0) {
-			$paths[] = \OC::$SERVERROOT . '/tests/lib/' . strtolower(str_replace('_', '/', substr($class, 5)) . '.php');
+		} elseif ($class === 'Test\\TestCase') {
+			// This File is considered public API, so we make sure that the class
+			// can still be loaded, although the PSR-4 paths have not been loaded.
+			$paths[] = \OC::$SERVERROOT . '/tests/lib/TestCase.php';
 		} elseif (strpos($class, 'Test\\') === 0) {
 			$paths[] = \OC::$SERVERROOT . '/tests/lib/' . strtolower(str_replace('\\', '/', substr($class, 5)) . '.php');
 		}
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 86bedc3f32..e2b980b1c8 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -8,6 +8,8 @@ if ($configDir) {
 
 require_once __DIR__ . '/../lib/base.php';
 
+\OC::$composerAutoloader->addPsr4('Test\\', OC::$SERVERROOT . '/tests/lib/', true);
+\OC::$composerAutoloader->addPsr4('Tests\\', OC::$SERVERROOT . '/tests/', true);
 \OC::$loader->addValidRoot(OC::$SERVERROOT . '/tests');
 
 // load all enabled apps
diff --git a/tests/lib/testcase.php b/tests/lib/TestCase.php
similarity index 100%
rename from tests/lib/testcase.php
rename to tests/lib/TestCase.php
diff --git a/tests/lib/autoloader.php b/tests/lib/autoloader.php
index adea702eca..3669f514be 100644
--- a/tests/lib/autoloader.php
+++ b/tests/lib/autoloader.php
@@ -37,18 +37,18 @@ class AutoLoader extends TestCase {
 		], $this->loader->findClass('OC_Files'));
 	}
 
+	public function testLoadTestTestCase() {
+		$this->assertEquals([
+			\OC::$SERVERROOT . '/tests/lib/TestCase.php'
+		], $this->loader->findClass('Test\TestCase'));
+	}
+
 	public function testLoadTestNamespace() {
 		$this->assertEquals([
 			\OC::$SERVERROOT . '/tests/lib/foo/bar.php'
 		], $this->loader->findClass('Test\Foo\Bar'));
 	}
 
-	public function testLoadTest() {
-		$this->assertEquals([
-			\OC::$SERVERROOT . '/tests/lib/foo/bar.php'
-		], $this->loader->findClass('Test_Foo_Bar'));
-	}
-
 	public function testLoadCore() {
 		$this->assertEquals([
 			\OC::$SERVERROOT . '/lib/private/legacy/foo/bar.php',