diff --git a/threadr/board/board.php b/threadr/board/board.php
index 3c27c10..6bc4ad0 100644
--- a/threadr/board/board.php
+++ b/threadr/board/board.php
@@ -23,7 +23,7 @@ foreach($statement->fetchAll() as $ROW) {
   // if this is a reply, build reference
   $reply_to = $ROW['reply_to'];
   if ($reply_to > -1) {
-    $reply_reference = "<p class=\"post_reply\" >This is a reply to <a href=./?id=$_GET['id']#$reply_to >this</a> message.</p>";
+    $reply_reference = "<p class=\"post_reply\" >This is a reply to <a href=./?id=" . $_GET['id'] . "#$reply_to >this</a> message.</p>";
   } else {
     $reply_reference = "";
   }