diff --git a/tests/PHPStan/Reflection/BetterReflection/SourceLocator/AutoloadSourceLocatorTest.php b/tests/PHPStan/Reflection/BetterReflection/SourceLocator/AutoloadSourceLocatorTest.php
new file mode 100644
index 0000000000..6d966bcc41
--- /dev/null
+++ b/tests/PHPStan/Reflection/BetterReflection/SourceLocator/AutoloadSourceLocatorTest.php
@@ -0,0 +1,29 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Reflection\BetterReflection\SourceLocator;
+
+use PHPStan\Parser\PhpParserDecorator;
+use PHPStan\Testing\TestCase;
+use Roave\BetterReflection\Reflector\ClassReflector;
+use Roave\BetterReflection\Reflector\FunctionReflector;
+use Roave\BetterReflection\SourceLocator\Ast\Locator;
+use TestSingleFileSourceLocator\AFoo;
+
+class AutoloadSourceLocatorTest extends TestCase
+{
+
+	public function testAutoloadEverythingInFile(): void
+	{
+		/** @var FunctionReflector $functionReflector */
+		$functionReflector = null;
+		$astLocator = new Locator(new PhpParserDecorator($this->getParser()), function () use (&$functionReflector): FunctionReflector {
+			return $functionReflector;
+		});
+		$locator = new AutoloadSourceLocator($astLocator);
+		$classReflector = new ClassReflector($locator);
+		$functionReflector = new FunctionReflector($locator, $classReflector);
+		$aFoo = $classReflector->reflect(AFoo::class);
+		$this->assertSame('a.php', basename($aFoo->getFileName()));
+	}
+
+}