diff --git a/include/class.thread.php b/include/class.thread.php
index 7ce4ec4035a761433234702c64d5f9b29f61f97c..9d17212962c26ac4a1b010275e04a4fe27bf4595 100644
--- a/include/class.thread.php
+++ b/include/class.thread.php
@@ -1332,13 +1332,17 @@ class ThreadBody /* extends SplString */ {
     }
 
     function __toString() {
-        return $this->display();
+        return (string) $this->body;
     }
 
     function toHtml() {
         return $this->display('html');
     }
 
+    function display($format=false) {
+        throw new Exception('display: Abstract dispplay() method not implemented');
+    }
+
     static function fromFormattedText($text, $format=false) {
         switch ($format) {
         case 'text':