diff --git a/mod/forum/search.php b/mod/forum/search.php
index 727743e3a2d..fe947b26885 100644
--- a/mod/forum/search.php
+++ b/mod/forum/search.php
@@ -204,7 +204,18 @@
         //Use highlight() with nonsense tags to spot search terms in the
         //actual text content first.          fiedorow - 9/2/2005
         $missing_terms = "";
-        $message = highlight($strippedsearch,format_text($post->message, $post->format, NULL, $course->id),
+
+        // Hack for posts of format FORMAT_PLAIN. Otherwise html tags added by
+        // the highlight() call bellow get stripped out by forum_print_post().
+        if ($post->format == FORMAT_PLAIN) {
+            $post->message = s($post->message); 
+            $post->message = rebuildnolinktag($post->message); 
+            $post->message = str_replace(' ', '  ', $post->message); 
+            $post->message = nl2br($post->message); 
+            $post->format = FORMAT_HTML;
+        }
+
+        $message = highlight($strippedsearch, format_text($post->message, $post->format, NULL, $course->id),
                 0,'<fgw9sdpq4>','</fgw9sdpq4>');
 
         foreach ($searchterms as $searchterm) {