diff --git a/includes/LST.php b/includes/LST.php
index 886d19d0..66355aad 100644
--- a/includes/LST.php
+++ b/includes/LST.php
@@ -55,6 +55,10 @@ public static function open( $parser, $part1 ) {
 
 			return false;
 		} else {
+			if ( !isset( $parser->mTemplatePath ) ) {
+				$parser->mTemplatePath = [];
+			}
+
 			$parser->mTemplatePath[$part1] = 1;
 
 			return true;