diff --git a/core/lib/Drupal/Core/Image/Image.php b/core/lib/Drupal/Core/Image/Image.php
index a8e86e0..402243f 100644
--- a/core/lib/Drupal/Core/Image/Image.php
+++ b/core/lib/Drupal/Core/Image/Image.php
@@ -71,7 +71,7 @@ class Image implements ImageInterface {
   /**
    * Constructs a new Image object.
    *
-   * @param string $source
+   * @param string|NULL $source
    *   The path to an image file, or NULL to construct the object with no
    *   image source.
    * @param \Drupal\Core\ImageToolkit\ImageToolkitInterface $toolkit
diff --git a/core/lib/Drupal/Core/Image/ImageFactory.php b/core/lib/Drupal/Core/Image/ImageFactory.php
index 3ca56d7..3bff021 100644
--- a/core/lib/Drupal/Core/Image/ImageFactory.php
+++ b/core/lib/Drupal/Core/Image/ImageFactory.php
@@ -65,7 +65,7 @@ public function getToolkitId() {
   /**
    * Constructs a new Image object.
    *
-   * @param string $source
+   * @param string|NULL $source
    *   The path to an image file, or NULL to construct the object with no
    *   image source.
    * @param string $toolkit_id