diff --git a/web/reinfo.php b/web/reinfo.php
index 3de46e0..4c9e260 100644
--- a/web/reinfo.php
+++ b/web/reinfo.php
@@ -93,7 +93,7 @@ if($ok){
   else if(strpos($row['error'],"php")!==false) $view_reinfo =  "error2";
   else if(strpos($row['error'],"PASS")!==false) $view_reinfo =  "error3";
   else if($OJ_SHOW_DIFF && $row && ($ok||$isRE) && ($OJ_TEST_RUN||is_valid($row['error'])||$ok)){ 
-    $view_reinfo = htmlentities(str_replace("\n\r","\n",$row['error']),ENT_QUOTES,"UTF-8");
+    $view_reinfo = "```" . htmlentities(str_replace("\n\r","\n",$row['error']),ENT_QUOTES,"UTF-8"). "```";
 
     $view_reinfo .="<br>$MSG_MARK:$mark";