diff --git a/src/wp-includes/IXR/class-IXR-message.php b/src/wp-includes/IXR/class-IXR-message.php
index 69af8aa2c0..013eae399a 100644
--- a/src/wp-includes/IXR/class-IXR-message.php
+++ b/src/wp-includes/IXR/class-IXR-message.php
@@ -9,12 +9,12 @@
  */
 class IXR_Message
 {
-    var $message;
-    var $messageType;  // methodCall / methodResponse / fault
-    var $faultCode;
-    var $faultString;
-    var $methodName;
-    var $params;
+    var $message     = false;
+    var $messageType = false;  // methodCall / methodResponse / fault
+    var $faultCode   = false;
+    var $faultString = false;
+    var $methodName  = '';
+    var $params      = array();
 
     // Current variable stacks
     var $_arraystructs = array();   // The stack used to keep track of the current array/struct