diff --git a/files/classes/external/stored_file_exporter.php b/files/classes/external/stored_file_exporter.php
index 1cc24061c85aa..c491170e971ed 100644
--- a/files/classes/external/stored_file_exporter.php
+++ b/files/classes/external/stored_file_exporter.php
@@ -54,6 +54,7 @@ public function __construct(stored_file $file, $related = array()) {
         $data->filepath = $file->get_filepath();
         $data->filename = $file->get_filename();
         $data->isdir = $file->is_directory();
+        $data->isimage = $file->is_valid_image();
         $data->timemodified = $file->get_timemodified();
         $data->timecreated = $file->get_timecreated();
         $data->filesize = $file->get_filesize();
@@ -94,6 +95,9 @@ protected static function define_properties() {
             'isdir' => array(
                 'type' => PARAM_BOOL
             ),
+            'isimage' => array(
+                'type' => PARAM_BOOL
+            ),
             'timemodified' => array(
                 'type' => PARAM_INT
             ),