diff --git a/core/lib/Drupal/Core/Image/Image.php b/core/lib/Drupal/Core/Image/Image.php
index 47448db..8377f1f 100644
--- a/core/lib/Drupal/Core/Image/Image.php
+++ b/core/lib/Drupal/Core/Image/Image.php
@@ -51,9 +51,9 @@ class Image implements ImageInterface {
    */
   public function __construct(ImageToolkitInterface $toolkit, $source = NULL) {
     $this->toolkit = $toolkit;
-    $this->getToolkit()->setImage($this);
     if ($source) {
       $this->source = $source;
+      $this->getToolkit()->setSource($this->source);
       // Defer image file validity check to the toolkit.
       if ($this->getToolkit()->parseFile()) {
         $this->fileSize = filesize($this->source);
diff --git a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php
index f5d8544..4481af3 100644
--- a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php
+++ b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php
@@ -32,11 +32,11 @@
   protected $configFactory;
 
   /**
-   * Image object this toolkit instance is tied to.
+   * Path of the image file.
    *
-   * @var \Drupal\Core\Image\ImageInterface
+   * @var string
    */
-  protected $image;
+  protected $source = '';
 
   /**
    * The image toolkit operation manager.
@@ -84,18 +84,22 @@ public function validateConfigurationForm(array &$form, FormStateInterface $form
   /**
    * {@inheritdoc}
    */
-  public function setImage(ImageInterface $image) {
-    if ($this->image) {
+  public function setSource($source) {
+    // If a previous image has been loaded, there is no way to know if the
+    // toolkit implementation needs to perform any additional actions like
+    // freeing memory. Therefore, the source image cannot be changed once set.
+    if ($this->source) {
       throw new \BadMethodCallException(__METHOD__ . '() may only be called once');
     }
-    $this->image = $image;
+    $this->source = $source;
+    return $this;
   }
 
   /**
    * {@inheritdoc}
    */
-  public function getImage() {
-    return $this->image;
+  public function getSource() {
+    return $this->source;
   }
 
   /**
diff --git a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php
index 8960504..1cf350e 100644
--- a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php
+++ b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php
@@ -53,23 +53,27 @@
 interface ImageToolkitInterface extends ContainerFactoryPluginInterface, PluginInspectionInterface, PluginFormInterface {
 
   /**
-   * Sets the image object that this toolkit instance is tied to.
+   * Sets the source path of the image file.
    *
-   * @param \Drupal\Core\Image\ImageInterface $image
-   *   The image that this toolkit instance will be tied to.
+   * @param string $source
+   *   The source path of the image file.
+   *
+   * @return \Drupal\Core\ImageToolkit\ImageToolkitInterface
+   *   An instance of the current toolkit object.
    *
    * @throws \BadMethodCallException
-   *   When called twice.
+   *   After being set initially, the source image cannot be changed.
    */
-  public function setImage(ImageInterface $image);
+  public function setSource($source);
 
   /**
-   * Gets the image object that this toolkit instance is tied to.
+   * Gets the source path of the image file.
    *
-   * @return \Drupal\Core\Image\ImageInterface
-   *   The image object that this toolkit instance is tied to.
+   * @return string
+   *   The source path of the image file, or an empty string if the source is
+   *   not set.
    */
-  public function getImage();
+  public function getSource();
 
   /**
    * Checks if the image is valid.
diff --git a/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php b/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
index 8738500..d607303 100644
--- a/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
+++ b/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
@@ -13,10 +13,10 @@
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\ImageToolkit\ImageToolkitBase;
 use Drupal\Core\ImageToolkit\ImageToolkitOperationManagerInterface;
+use Drupal\Core\StreamWrapper\StreamWrapperInterface;
 use Drupal\Core\StreamWrapper\StreamWrapperManagerInterface;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
-use Drupal\Core\StreamWrapper\StreamWrapperInterface;
 
 /**
  * Defines the GD2 toolkit for image manipulation within Drupal.
@@ -65,7 +65,7 @@ class GDToolkit extends ImageToolkitBase {
   protected $streamWrapperManager;
 
   /**
-   * Constructs a TestToolkit object.
+   * Constructs a GDToolkit object.
    *
    * @param array $configuration
    *   A configuration array containing information about the plugin instance.
@@ -88,6 +88,17 @@ public function __construct(array $configuration, $plugin_id, array $plugin_defi
   }
 
   /**
+   * Destructs a GDToolkit object.
+   *
+   * Frees memory associated with a GD image resource.
+   */
+  public function __destruct() {
+    if (is_resource($this->resource)) {
+      imagedestroy($this->resource);
+    }
+  }
+
+  /**
    * {@inheritdoc}
    */
   public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
@@ -108,9 +119,13 @@ public static function create(ContainerInterface $container, array $configuratio
    * @param resource $resource
    *   The GD image resource.
    *
-   * @return $this
+   * @return \Drupal\system\Plugin\ImageToolkit\GDToolkit
+   *   An instance of the current toolkit object.
    */
   public function setResource($resource) {
+    if (!is_resource($resource) || get_resource_type($resource) != 'gd') {
+      throw new \InvalidArgumentException('Invalid resource argument');
+    }
     $this->preLoadInfo = NULL;
     $this->resource = $resource;
     return $this;
@@ -123,7 +138,7 @@ public function setResource($resource) {
    *   The GD image resource, or NULL if not available.
    */
   public function getResource() {
-    if (!$this->resource) {
+    if (!is_resource($this->resource)) {
       $this->load();
     }
     return $this->resource;
@@ -167,7 +182,7 @@ protected function load() {
     }
 
     $function = 'imagecreatefrom' . image_type_to_extension($this->getType(), FALSE);
-    if (function_exists($function) && $resource = $function($this->getImage()->getSource())) {
+    if (function_exists($function) && $resource = $function($this->getSource())) {
       $this->setResource($resource);
       if (imageistruecolor($resource)) {
         return TRUE;
@@ -242,7 +257,7 @@ public function save($destination) {
    * {@inheritdoc}
    */
   public function parseFile() {
-    $data = @getimagesize($this->getImage()->getSource());
+    $data = @getimagesize($this->getSource());
     if ($data && in_array($data[2], static::supportedTypes())) {
       $this->setType($data[2]);
       $this->preLoadInfo = $data;
diff --git a/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Desaturate.php b/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Desaturate.php
index 09457df..b4bc1ee 100644
--- a/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Desaturate.php
+++ b/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Desaturate.php
@@ -34,7 +34,7 @@ protected function arguments() {
   protected function execute(array $arguments) {
     // PHP installations using non-bundled GD do not have imagefilter.
     if (!function_exists('imagefilter')) {
-      $this->logger->notice("The image '@file' could not be desaturated because the imagefilter() function is not available in this PHP installation.", array('@file' => $this->getToolkit()->getImage()->getSource()));
+      $this->logger->notice("The image '@file' could not be desaturated because the imagefilter() function is not available in this PHP installation.", array('@file' => $this->getToolkit()->getSource()));
       return FALSE;
     }
 
diff --git a/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Rotate.php b/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Rotate.php
index 0284b42..e7e3a6c 100644
--- a/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Rotate.php
+++ b/core/modules/system/src/Plugin/ImageToolkit/Operation/gd/Rotate.php
@@ -94,7 +94,7 @@ protected function validateArguments(array $arguments) {
   protected function execute(array $arguments) {
     // PHP installations using non-bundled GD do not have imagerotate.
     if (!function_exists('imagerotate')) {
-      $this->logger->notice('The image %file could not be rotated because the imagerotate() function is not available in this PHP installation.', array('%file' => $this->getToolkit()->getImage()->getSource()));
+      $this->logger->notice('The image %file could not be rotated because the imagerotate() function is not available in this PHP installation.', array('%file' => $this->getToolkit()->getSource()));
       return FALSE;
     }
 
diff --git a/core/modules/system/src/Tests/Image/ToolkitGdTest.php b/core/modules/system/src/Tests/Image/ToolkitGdTest.php
index d7f55dc..da8126b 100644
--- a/core/modules/system/src/Tests/Image/ToolkitGdTest.php
+++ b/core/modules/system/src/Tests/Image/ToolkitGdTest.php
@@ -8,8 +8,8 @@
 namespace Drupal\system\Tests\Image;
 
 use Drupal\Core\Image\ImageInterface;
-use \Drupal\simpletest\KernelTestBase;
 use Drupal\Component\Utility\SafeMarkup;
+use Drupal\simpletest\KernelTestBase;
 
 /**
  * Tests that core image manipulations work properly: scale, resize, rotate,
@@ -402,6 +402,18 @@ function testManipulations() {
   }
 
   /**
+   * Tests that GD resources are freed from memory.
+   */
+  public function testResourceDestruction() {
+    $image = $this->imageFactory->get(drupal_get_path('module', 'simpletest') . '/files/image-test.png');
+    $res = $image->getToolkit()->getResource();
+    $this->assertTrue(is_resource($res), 'Successfully loaded image resource.');
+    // Force the toolkit to go out of scope.
+    $image = NULL;
+    $this->assertFalse(is_resource($res), 'Image resource was destroyed after losing scope.');
+  }
+
+  /**
    * Tests loading an image whose transparent color index is out of range.
    */
   function testTransparentColorOutOfRange() {
diff --git a/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php b/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
index 7513ac2..a018b3c 100644
--- a/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
+++ b/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
@@ -138,7 +138,7 @@ public function isValid() {
    */
   public function parseFile() {
     $this->logCall('parseFile', func_get_args());
-    $data = @getimagesize($this->getImage()->getSource());
+    $data = @getimagesize($this->getSource());
     if ($data && in_array($data[2], static::supportedTypes())) {
       $this->setType($data[2]);
       $this->width = $data[0];