diff --git a/_config.php b/_config.php
index 07af9ac..1b8cbe4 100644
--- a/_config.php
+++ b/_config.php
@@ -1,4 +1,9 @@
 <?php
+// Ensure compatibility with PHP 7.2 ("object" is a reserved word),
+// with SilverStripe 3.6 (using Object) and SilverStripe 3.7 (using SS_Object)
+if (!class_exists('SS_Object')) {
+    class_alias('Object', 'SS_Object');
+}
 
 // add the extension to pages
 if (class_exists('SiteTree')) {
diff --git a/code/GoogleSitemap.php b/code/GoogleSitemap.php
index fe169b9..3d0215a 100644
--- a/code/GoogleSitemap.php
+++ b/code/GoogleSitemap.php
@@ -37,7 +37,7 @@
  *
  * @package googlesitemaps
  */
-class GoogleSitemap extends Object
+class GoogleSitemap extends SS_Object
 {
 
     /**