diff --git a/src/DependencyInjection/MakerExtension.php b/src/DependencyInjection/MakerExtension.php
index 575408fa1..8051d8919 100644
--- a/src/DependencyInjection/MakerExtension.php
+++ b/src/DependencyInjection/MakerExtension.php
@@ -39,6 +39,9 @@ public function load(array $configs, ContainerBuilder $container)
 
         $rootNamespace = trim($config['root_namespace'], '\\');
 
+        $autoloaderFinderDefinition = $container->getDefinition('maker.autoloader_finder');
+        $autoloaderFinderDefinition->replaceArgument(0, $rootNamespace);
+
         $makeCommandDefinition = $container->getDefinition('maker.generator');
         $makeCommandDefinition->replaceArgument(1, $rootNamespace);
 
diff --git a/src/Resources/config/services.xml b/src/Resources/config/services.xml
index 6440feb70..1031517e4 100644
--- a/src/Resources/config/services.xml
+++ b/src/Resources/config/services.xml
@@ -13,7 +13,9 @@
                 <argument>%kernel.project_dir%</argument>
             </service>
 
-            <service id="maker.autoloader_finder" class="Symfony\Bundle\MakerBundle\Util\ComposerAutoloaderFinder" />
+            <service id="maker.autoloader_finder" class="Symfony\Bundle\MakerBundle\Util\ComposerAutoloaderFinder" >
+                <argument /> <!-- root namespace -->
+            </service>
 
             <service id="maker.autoloader_util" class="Symfony\Bundle\MakerBundle\Util\AutoloaderUtil">
                 <argument type="service" id="maker.autoloader_finder" />
diff --git a/src/Util/ComposerAutoloaderFinder.php b/src/Util/ComposerAutoloaderFinder.php
index 00d28d58e..db68dbe2d 100644
--- a/src/Util/ComposerAutoloaderFinder.php
+++ b/src/Util/ComposerAutoloaderFinder.php
@@ -19,11 +19,21 @@
  */
 class ComposerAutoloaderFinder
 {
+    private $rootNamespace;
+
     /**
      * @var ClassLoader|null
      */
     private $classLoader = null;
 
+    public function __construct(string $rootNamespace)
+    {
+        $this->rootNamespace = [
+            'psr0' => rtrim($rootNamespace, '\\'),
+            'psr4' => rtrim($rootNamespace, '\\').'\\',
+        ];
+    }
+
     public function getClassLoader(): ClassLoader
     {
         if (null === $this->classLoader) {
@@ -31,7 +41,7 @@ public function getClassLoader(): ClassLoader
         }
 
         if (null === $this->classLoader) {
-            throw new \Exception('Composer ClassLoader not found!');
+            throw new \Exception("Could not find a Composer autoloader that autoloads from '{$this->rootNamespace['psr4']}'");
         }
 
         return $this->classLoader;
@@ -45,19 +55,61 @@ private function findComposerClassLoader()
         $autoloadFunctions = spl_autoload_functions();
 
         foreach ($autoloadFunctions as $autoloader) {
-            if (\is_array($autoloader) && isset($autoloader[0]) && \is_object($autoloader[0])) {
-                if ($autoloader[0] instanceof ClassLoader) {
-                    return $autoloader[0];
-                }
-
-                if ($autoloader[0] instanceof DebugClassLoader
-                    && \is_array($autoloader[0]->getClassLoader())
-                    && $autoloader[0]->getClassLoader()[0] instanceof ClassLoader) {
-                    return $autoloader[0]->getClassLoader()[0];
-                }
+            $classLoader = $this->extractComposerClassLoader($autoloader);
+            if (null === $classLoader) {
+                continue;
+            }
+
+            $finalClassLoader = $this->locateMatchingClassLoader($classLoader);
+            if (null !== $finalClassLoader) {
+                return $finalClassLoader;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @return ClassLoader|null
+     */
+    private function extractComposerClassLoader(array $autoloader)
+    {
+        if (isset($autoloader[0]) && \is_object($autoloader[0])) {
+            if ($autoloader[0] instanceof ClassLoader) {
+                return $autoloader[0];
+            }
+            if ($autoloader[0] instanceof DebugClassLoader
+                && \is_array($autoloader[0]->getClassLoader())
+                && $autoloader[0]->getClassLoader()[0] instanceof ClassLoader) {
+                return $autoloader[0]->getClassLoader()[0];
             }
         }
 
         return null;
     }
+
+    /**
+     * @return ClassLoader|null
+     */
+    private function locateMatchingClassLoader(ClassLoader $classLoader)
+    {
+        $makerClassLoader = null;
+        foreach ($classLoader->getPrefixesPsr4() as $prefix => $paths) {
+            if ('Symfony\\Bundle\\MakerBundle\\' === $prefix) {
+                $makerClassLoader = $classLoader;
+            }
+            if (0 === strpos($this->rootNamespace['psr4'], $prefix)) {
+                return $classLoader;
+            }
+        }
+
+        foreach ($classLoader->getPrefixes() as $prefix => $paths) {
+            if (0 === strpos($this->rootNamespace['psr0'], $prefix)) {
+                return $classLoader;
+            }
+        }
+
+        // We can default to using the autoloader containing this component if none are matching.
+        return $makerClassLoader ?: null;
+    }
 }
diff --git a/tests/Maker/FunctionalTest.php b/tests/Maker/FunctionalTest.php
index 64f765d7a..ff7e45312 100644
--- a/tests/Maker/FunctionalTest.php
+++ b/tests/Maker/FunctionalTest.php
@@ -205,7 +205,7 @@ public function getCommandTests()
             ])
             ->addExtraDependencies('orm')
             ->setFixtureFilesPath(__DIR__.'/../fixtures/MakeFormForEntity')
-		];
+        ];
 
         yield 'form_for_non_entity_dto' => [MakerTestDetails::createTest(
             $this->getMakerInstance(MakeForm::class),
diff --git a/tests/Util/AutoloaderUtilTest.php b/tests/Util/AutoloaderUtilTest.php
index f07e8c2c9..c95ba77a2 100644
--- a/tests/Util/AutoloaderUtilTest.php
+++ b/tests/Util/AutoloaderUtilTest.php
@@ -87,6 +87,7 @@ private function createComposerAutoloaderFinder(array $composerJsonParams = null
         /** @var \PHPUnit_Framework_MockObject_MockObject|ComposerAutoloaderFinder $finder */
         $finder = $this
             ->getMockBuilder(ComposerAutoloaderFinder::class)
+            ->setConstructorArgs(['App\\'])
             ->getMock();
 
         $finder
diff --git a/tests/Util/ComposerAutoloaderFinderTest.php b/tests/Util/ComposerAutoloaderFinderTest.php
index d76c473e3..5adc155cc 100644
--- a/tests/Util/ComposerAutoloaderFinderTest.php
+++ b/tests/Util/ComposerAutoloaderFinderTest.php
@@ -10,6 +10,8 @@ class ComposerAutoloaderFinderTest extends TestCase
 {
     public static $getSplAutoloadFunctions = 'spl_autoload_functions';
 
+    private static $rootNamespace = 'Fake\\It\\Till\\You\\Make\\It\\';
+
     /**
      * @after
      */
@@ -18,9 +20,20 @@ public function resetAutoloadFunction()
         self::$getSplAutoloadFunctions = 'spl_autoload_functions';
     }
 
-    public function testGetClassLoader()
+    public function providerNamespaces(): \Generator
     {
-        $loader = (new ComposerAutoloaderFinder())->getClassLoader();
+        yield 'Configured PSR-0' => [rtrim(static::$rootNamespace, '\\'), null];
+        yield 'Configured PSR-4' => [null, static::$rootNamespace];
+        yield 'Fallback default' => [null, 'Symfony\\Bundle\\MakerBundle\\'];
+    }
+
+    /**
+     * @dataProvider providerNamespaces
+     */
+    public function testGetClassLoader($psr0, $psr4)
+    {
+        $this->setupAutoloadFunctions($psr0, $psr4);
+        $loader = (new ComposerAutoloaderFinder(static::$rootNamespace))->getClassLoader();
 
         $this->assertInstanceOf(ClassLoader::class, $loader, 'Wrong ClassLoader found');
     }
@@ -35,7 +48,26 @@ public function testGetClassLoaderWhenItIsEmpty()
         };
 
         // throws \Exception
-        (new ComposerAutoloaderFinder())->getClassLoader();
+        (new ComposerAutoloaderFinder(static::$rootNamespace))->getClassLoader();
+    }
+
+    /**
+     * @param string|null $psr0
+     * @param string|null $psr4
+     */
+    private function setupAutoloadFunctions($psr0, $psr4)
+    {
+        self::$getSplAutoloadFunctions = function () use ($psr0, $psr4) {
+            $loader = new ClassLoader();
+            if ($psr0) {
+                $loader->add($psr0, __DIR__);
+            }
+            if ($psr4) {
+                $loader->addPsr4($psr4, __DIR__);
+            }
+
+            return [[$loader, 'loadClass']];
+        };
     }
 }