diff --git a/core/lib/Drupal/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumper.php b/core/lib/Drupal/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumper.php
index 949950f..1837cf4 100644
--- a/core/lib/Drupal/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumper.php
+++ b/core/lib/Drupal/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumper.php
@@ -252,7 +252,10 @@ protected function getServiceDefinition(Definition $definition) {
       }
     }
 
-    $service['shared'] = $definition->isShared();
+    // By default services are shared, so just provide the flag, when needed.
+    if ($definition->isShared() === FALSE) {
+      $service['shared'] = $definition->isShared();
+    }
 
     if (($decorated = $definition->getDecoratedService()) !== NULL) {
       throw new InvalidArgumentException("The 'decorated' definition is not supported by the Drupal 8 run-time container. The Container Builder should have resolved that during the DecoratorServicePass compiler pass.");
diff --git a/core/tests/Drupal/Tests/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumperTest.php b/core/tests/Drupal/Tests/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumperTest.php
index 0a227d7..c1c6058 100644
--- a/core/tests/Drupal/Tests/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumperTest.php
+++ b/core/tests/Drupal/Tests/Component/DependencyInjection/Dumper/OptimizedPhpArrayDumperTest.php
@@ -267,6 +267,10 @@ public function getDefinitionsDataProvider() {
       ) + $base_service_definition;
 
       $service_definitions[] = array(
+        'shared' => FALSE,
+      ) + $base_service_definition;
+
+      $service_definitions[] = array(
         'lazy' => TRUE,
       ) + $base_service_definition;