diff --git a/src/ConfigElement/Operator/Concatenator.php b/src/ConfigElement/Operator/Concatenator.php
index b4003c4..20eb81e 100644
--- a/src/ConfigElement/Operator/Concatenator.php
+++ b/src/ConfigElement/Operator/Concatenator.php
@@ -32,6 +32,7 @@ public function __construct($config, $context = null)
     public function getLabeledValue($object)
     {
         $result = new \stdClass();
+        $result->value = null;
         $result->label = $this->label;
 
         $hasValue = true;
@@ -46,8 +47,10 @@ public function getLabeledValue($object)
             $value = $c->getLabeledValue($object) ? $c->getLabeledValue($object)->value : null;
 
             if (!$hasValue) {
-                if (!empty($value) || ((method_exists($value, 'isEmpty') && !$value->isEmpty()))) {
-                    $hasValue = true;
+                if (is_object($value) && method_exists($value, 'isEmpty')) {
+                    $hasValue = !$value->isEmpty();
+                } else {
+                    $hasValue = !empty($value);
                 }
             }