diff --git a/lib/Drupal/mongodb/FileUsage.php b/lib/Drupal/mongodb/FileUsage.php
new file mode 100644
index 0000000..f91dd73
--- /dev/null
+++ b/lib/Drupal/mongodb/FileUsage.php
@@ -0,0 +1,123 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\mongodb\FileUsage.
+ */
+
+namespace Drupal\mongodb;
+
+use Drupal\file\Plugin\Core\Entity\File;
+
+/**
+ * Defines the mongodb file usage backend.
+ */
+class FileUsage extends FileUsageBase {
+
+  /**
+   * The mongodb factory registered as a service.
+   *
+   * @var Drupal\mongodb\MongoCollectionFactory
+   */
+  protected $database;
+
+  /**
+   * The name of the mongodb collection used to store file usage information.
+   *
+   * @var string
+   */
+  protected $collection;
+
+  /**
+   * Construct the DatabaseFileUsageBackend.
+   *
+   * @param Drupal\mongodb\MongoCollectionFactory $database
+   *   The database connection which will be used to store the file usage
+   *   information.
+   * @param string $collection
+   *   (optional) The collection to store file usage info. Defaults to 'file_usage'.
+   */
+  public function __construct(MongoCollectionFactory $database, $collection = 'file_usage') {
+    $this->database = $database;
+    $this->collection = $collection;
+  }
+
+  // @todo we need to add indexes when we install the module.
+
+  /**
+   * Implements Drupal\file\FileUsage\FileUsageInterface::add().
+   */
+  public function add(File $file, $module, $type, $id, $count = 1) {
+    $key = array(
+      'fid' => $file->fid,
+      'module' => $module,
+      'type' => $type,
+      'id' => $id,
+    );
+    // @index fid, module, type, id.
+    $this->database->get($this->collection)->update($key, array('$inc' => $count), array('upsert' => TRUE));
+
+    parent::add($file, $module, $type, $id, $count);
+  }
+
+  /**
+   * Implements Drupal\file\FileUsage\FileUsageInterface::delete().
+   */
+  public function delete(File $file, $module, $type = NULL, $id = NULL, $count = 1) {
+    if ($count > 0) {
+      // Delete entries that have a exact or less value to prevent empty rows.
+      $key = array(
+        'fid' => $file->fid,
+        'module' => $module,
+      );
+
+      if ($type && $id) {
+        $key['type'] = $type;
+        $key['id'] = $id;
+      }
+
+      if ($count) {
+        $key['count']['$lte'] = $count;
+      }
+
+      // @index fid, module.
+      // @index fid, module, count.
+      // @index fid, module, type, id.
+      // @index fid, module, type, id, count.
+      $record_count = $this->database->get($this->collection)->count($key);
+
+      // If the row has more than the specified count decrement it by that number.
+      if (!$record_count) {
+        unset($key['count']);
+        // Assume that we do not want to update if item is collection.
+        try {
+          // @index fid, module.
+          // @index fid, module, type, id.
+          $this->database->get($this->collection)->update($key, array('$inc' => -1 * $count));
+        }
+        catch {
+        }
+      }
+    }
+
+    parent::delete($file, $module, $type, $id, $count);
+  }
+
+  /**
+   * Implements Drupal\file\FileUsage\FileUsageInterface::listUsage().
+   */
+  public function listUsage(File $file) {
+    $key = array(
+      'fid' => $file->fid,
+      'count' => array(
+        '$gt' => 0,
+      ),
+    );
+    $results = $this->database->get($this->collection)->find($key, array('module' => TRUE, 'type' => TRUE, 'id' => TRUE, 'count' => TRUE));
+    $references = array();
+    foreach ($results as $usage) {
+      $references[$usage['module']][$usage['type']][$usage['id']] = $usage['count'];
+    }
+    return $references;
+  }
+}