diff --git a/phpBB/search.php b/phpBB/search.php
index ae3d9b73a3..a2feeab37c 100644
--- a/phpBB/search.php
+++ b/phpBB/search.php
@@ -808,8 +808,11 @@ if ($keywords || $author || $author_id || $search_id || $submit)
 					$message = smiley_text($message);
 				}
 
-				// post highlighting
-				$message = preg_replace('#(?!(?:<(?:s(?:cript|tyle))?)[^<]*)(?<!\w)(' . $hilit . ')(?!\w|[^<>]*(?:</s(?:cript|tyle))?>)#is', '<span class="posthilit">$1</span>', $message);
+				if ($hilit)
+				{
+					// post highlighting
+					$message = preg_replace('#(?!(?:<(?:s(?:cript|tyle))?)[^<]*)(?<!\w)(' . $hilit . ')(?!\w|[^<>]*(?:</s(?:cript|tyle))?>)#is', '<span class="posthilit">$1</span>', $message);
+				}
 
 				$tpl_ary = array(
 					'POSTER_NAME'		=> ($row['poster_id'] == ANONYMOUS) ? ((!empty($row['post_username'])) ? $row['post_username'] : $user->lang['GUEST']) : $row['username'],