diff --git a/core/modules/image/src/Plugin/Field/FieldType/ImageItem.php b/core/modules/image/src/Plugin/Field/FieldType/ImageItem.php
index c83e143..ce94894 100644
--- a/core/modules/image/src/Plugin/Field/FieldType/ImageItem.php
+++ b/core/modules/image/src/Plugin/Field/FieldType/ImageItem.php
@@ -9,6 +9,7 @@
 use Drupal\Core\StreamWrapper\StreamWrapperInterface;
 use Drupal\Core\TypedData\DataDefinition;
 use Drupal\file\Entity\File;
+use Drupal\file\FileInterface;
 use Drupal\file\Plugin\Field\FieldType\FileItem;
 
 /**
@@ -313,13 +314,18 @@ public function preSave() {
     $height = $this->height;
 
     // Determine the dimensions if necessary.
-    if (empty($width) || empty($height)) {
-      $image = \Drupal::service('image.factory')->get($this->entity->getFileUri());
-      if ($image->isValid()) {
-        $this->width = $image->getWidth();
-        $this->height = $image->getHeight();
+    if (($this->entity instanceof FileInterface)) {
+      if (empty($width) || empty($height)) {
+        $image = \Drupal::service('image.factory')->get($this->entity->getFileUri());
+        if ($image->isValid()) {
+          $this->width = $image->getWidth();
+          $this->height = $image->getHeight();
+        }
       }
     }
+    else {
+      trigger_error(sprintf("A malformed file was provided. Cannot determine its dimensions."), E_USER_WARNING);
+    }
   }
 
   /**
diff --git a/core/modules/image/tests/src/Kernel/ImageItemTest.php b/core/modules/image/tests/src/Kernel/ImageItemTest.php
index dea4534..0c6fcfa 100644
--- a/core/modules/image/tests/src/Kernel/ImageItemTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageItemTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\image\Kernel;
 
+use Drupal\Core\Entity\EntityStorageException;
 use Drupal\Core\Field\FieldItemInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
@@ -108,6 +109,15 @@ public function testImageItem() {
     $this->assertEqual($entity->image_test->height, $image->getHeight());
     $this->assertEqual($entity->image_test->alt, $new_alt);
 
+    // Validate entity is a file and don't gather dimensions if it is not.
+    $entity->image_test = NULL;
+    $entity->image_test->target_id = 0;
+    $this->setExpectedException(EntityStorageException::class, "A malformed file was provided. Cannot determine its dimensions.");
+    $entity->save();
+
+    $this->assertEmpty($entity->image_test->width);
+    $this->assertEmpty($entity->image_test->height);
+
     // Check that the image item can be set to the referenced file directly.
     $entity->image_test = $this->image;
     $this->assertEqual($entity->image_test->target_id, $this->image->id());