diff --git a/admin/code/LeftAndMain.php b/admin/code/LeftAndMain.php
index 20b652fa963..1a12da84c1f 100644
--- a/admin/code/LeftAndMain.php
+++ b/admin/code/LeftAndMain.php
@@ -1172,7 +1172,7 @@ public function PreviewLink() {
 	 * @return string
 	 */
 	public function CMSVersion() {
-		if(file_exists(CMS_PATH . '/silverstripe_version')) {
+		if(defined('CMS_PATH') && file_exists(CMS_PATH . '/silverstripe_version')) {
 			$sapphireVersion = file_get_contents(CMS_PATH . '/silverstripe_version');
 		} else {
 			$sapphireVersion = file_get_contents(SAPPHIRE_PATH . '/silverstripe_version');