diff --git a/csv-normaliser/main.php b/csv-normaliser/main.php
index 9bc2ee5..c02682c 100644
--- a/csv-normaliser/main.php
+++ b/csv-normaliser/main.php
@@ -129,7 +129,7 @@ if (($handle = fopen($inputFile, "r")) !== FALSE) {
                 $name_patterns[] = "^" . $first_name . ".*";
             }
             if ($last_name != $first_name && strlen($last_name)) {
-                "^" . $last_name . ".*";
+                $name_patterns[] = "^" . $last_name . ".*";
             }
 
             $regex_groups = array_map(function($x) { return "(?:" . $x . ")"; }, $name_patterns);