diff --git a/src/Publisher.php b/src/Publisher.php
index 9d8432290778bbf2fe203154ecf99921a120ed10..3a4b3cbfa381be2ab06e2e3de83155d7ce482631 100644
--- a/src/Publisher.php
+++ b/src/Publisher.php
@@ -337,7 +337,7 @@ class Publisher
             } else {
                 if (isset($variables[$name])) {
                     foreach ($variables[$name] as $vElement) {
-                        $this->setVariable($vElement, $val);
+                        $this->setVariable($vElement, $val ? $val : '');
                     }
                 }
                 if (false !== strpos($name, '@')) {