diff --git a/mod/forum/classes/local/renderers/discussion_list.php b/mod/forum/classes/local/renderers/discussion_list.php
index dcec49415ccb..e57ee7e915dd 100644
--- a/mod/forum/classes/local/renderers/discussion_list.php
+++ b/mod/forum/classes/local/renderers/discussion_list.php
@@ -230,7 +230,7 @@ public function render(
             $exportedposts = ($this->postprocessfortemplate) ($discussions, $user, $forum);
         }
 
-        $baseurl = new \moodle_url($PAGE->url, array('o' => $sortorder));
+        $baseurl = new \moodle_url($PAGE->url, ['o' => $sortorder, 's' => $pagesize]);
 
         $forumview = array_merge(
             $forumview,
diff --git a/mod/forum/view.php b/mod/forum/view.php
index b0af745d1e7c..8504bb2b08d0 100644
--- a/mod/forum/view.php
+++ b/mod/forum/view.php
@@ -41,7 +41,7 @@
 $pageno = optional_param('page', 0, PARAM_INT);
 $search = optional_param('search', '', PARAM_CLEAN);
 $pageno = optional_param('p', $pageno, PARAM_INT);
-$pagesize = optional_param('s', 0, PARAM_INT);
+$pagesize = optional_param('s', $CFG->forum_manydiscussions ?? 0, PARAM_INT);
 $sortorder = optional_param('o', null, PARAM_INT);
 
 if (!$cmid && !$forumid) {