diff --git a/calendar/lib.php b/calendar/lib.php
index 654a5b9fb57..fc8d32b972e 100644
--- a/calendar/lib.php
+++ b/calendar/lib.php
@@ -798,7 +798,7 @@ function calendar_get_events_by_id($eventids) {
  * @return string $content return available control for the calender in html
  */
 function calendar_top_controls($type, $data) {
-    global $CFG;
+    global $CFG, $PAGE;
     $content = '';
     if(!isset($data['d'])) {
         $data['d'] = 1;
@@ -821,6 +821,7 @@ function calendar_top_controls($type, $data) {
 
     $data['m'] = $date['mon'];
     $data['y'] = $date['year'];
+    $urlbase = $PAGE->url;
 
     //Accessibility: calendar block controls, replaced <table> with <div>.
     //$nexttext = link_arrow_right(get_string('monthnext', 'access'), $url='', $accesshide=true);
@@ -830,8 +831,8 @@ function calendar_top_controls($type, $data) {
         case 'frontpage':
             list($prevmonth, $prevyear) = calendar_sub_month($data['m'], $data['y']);
             list($nextmonth, $nextyear) = calendar_add_month($data['m'], $data['y']);
-            $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), 'index.php?', 0, $nextmonth, $nextyear, $accesshide=true);
-            $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), 'index.php?', 0, $prevmonth, $prevyear, true);
+            $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), $urlbase, 0, $nextmonth, $nextyear, true);
+            $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), $urlbase, 0, $prevmonth, $prevyear, true);
 
             $calendarlink = calendar_get_link_href(new moodle_url(CALENDAR_URL.'view.php', array('view'=>'month')), 1, $data['m'], $data['y']);
             if (!empty($data['id'])) {
@@ -857,8 +858,8 @@ function calendar_top_controls($type, $data) {
         case 'course':
             list($prevmonth, $prevyear) = calendar_sub_month($data['m'], $data['y']);
             list($nextmonth, $nextyear) = calendar_add_month($data['m'], $data['y']);
-            $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), 'view.php?id='.$data['id'].'&amp;', 0, $nextmonth, $nextyear, $accesshide=true);
-            $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), 'view.php?id='.$data['id'].'&amp;', 0, $prevmonth, $prevyear, true);
+            $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), $urlbase, 0, $nextmonth, $nextyear, true);
+            $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), $urlbase, 0, $prevmonth, $prevyear, true);
 
             $calendarlink = calendar_get_link_href(new moodle_url(CALENDAR_URL.'view.php', array('view'=>'month')), 1, $data['m'], $data['y']);
             if (!empty($data['id'])) {