diff --git a/src/Message/AbstractMessage.php b/src/Message/AbstractMessage.php
index a796b67..0b51d57 100644
--- a/src/Message/AbstractMessage.php
+++ b/src/Message/AbstractMessage.php
@@ -26,7 +26,7 @@ public function __construct(array $data = [])
             $methodName = 'set' . ucfirst($k);
             if (method_exists($this, $methodName)) {
                 $this->{$methodName}($v);
-            } else {
+            } elseif (isset($this->{$k})) {
                 $this->{$k} = $v;
             }
         }