diff --git a/mod/forum/index.php b/mod/forum/index.php
index 5e0b941c507..85d866de31a 100644
--- a/mod/forum/index.php
+++ b/mod/forum/index.php
@@ -221,7 +221,7 @@
                 $forumlink = $forumname;
                 $discussionlink = $count;
             } else {
-                if ($forum->visible) {
+                if (!empty($forum->visible)) {
                     $style = '';
                 } else {
                     $style = 'class="dimmed"';