diff --git a/src/Symfony/Component/DependencyInjection/Compiler/RemoveUnusedDefinitionsPass.php b/src/Symfony/Component/DependencyInjection/Compiler/RemoveUnusedDefinitionsPass.php
index 1bebd7ad5c..f2d6b07514 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/RemoveUnusedDefinitionsPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/RemoveUnusedDefinitionsPass.php
@@ -60,7 +60,7 @@ class RemoveUnusedDefinitionsPass extends AbstractRecursivePass implements Repea
                 $ids = $this->connectedIds;
                 $this->connectedIds = array();
                 foreach ($ids as $id) {
-                    if (!isset($connectedIds[$id]) && $container->has($id)) {
+                    if (!isset($connectedIds[$id]) && $container->hasDefinition($id)) {
                         $connectedIds[$id] = true;
                         $this->processValue($container->getDefinition($id));
                     }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/RemoveUnusedDefinitionsPassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/RemoveUnusedDefinitionsPassTest.php
index c90a8d6728..c04eacbb75 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/RemoveUnusedDefinitionsPassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/RemoveUnusedDefinitionsPassTest.php
@@ -127,6 +127,21 @@ class RemoveUnusedDefinitionsPassTest extends TestCase
         $this->assertSame(1, $envCounters['FOOBAR']);
     }
 
+    public function testProcessDoesNotErrorOnServicesThatDoNotHaveDefinitions()
+    {
+        $container = new ContainerBuilder();
+        $container
+            ->register('defined')
+            ->addArgument(new Reference('not.defined'))
+            ->setPublic(true);
+
+        $container->set('not.defined', new \StdClass());
+
+        $this->process($container);
+
+        $this->assertFalse($container->hasDefinition('not.defined'));
+    }
+
     protected function process(ContainerBuilder $container)
     {
         (new RemoveUnusedDefinitionsPass())->process($container);