diff --git a/admin/block.php b/admin/block.php
index ccc58915db3..da61afcf703 100644
--- a/admin/block.php
+++ b/admin/block.php
@@ -23,7 +23,7 @@
     // so we can strip them from the submitted data BEFORE handling it.
     $hiddendata = array(
         'block' => $blockid,
-        'sesskey' => $USER->sesskey
+        'sesskey' => sesskey()
     );
 
     /// If data submitted, then process and store.
diff --git a/admin/blocks.php b/admin/blocks.php
index 10e070142c3..cfe59e933b6 100644
--- a/admin/blocks.php
+++ b/admin/blocks.php
@@ -181,7 +181,7 @@
         $count      = $DB->count_records('block_instance', array('blockid'=>$blockid, 'pagetype'=>'course-view'));
 
         if ($count>0) {
-            $blocklist = "<a href=\"{$CFG->wwwroot}/course/search.php?blocklist=$blockid&amp;sesskey={$USER->sesskey}\" ";
+            $blocklist = "<a href=\"{$CFG->wwwroot}/course/search.php?blocklist=$blockid&amp;sesskey=".sesskey()."\" ";
             $blocklist .= "title=\"$strshowblockcourse\" >$totalcount</a>";
         }
         else {
diff --git a/admin/enrol_config.php b/admin/enrol_config.php
index 76b83013fa5..1f7ae122228 100644
--- a/admin/enrol_config.php
+++ b/admin/enrol_config.php
@@ -22,7 +22,7 @@
             print_error('confirmsesskeybad', 'error');
         }
         if ($enrolment->process_config($frm)) {
-            redirect("enrol.php?sesskey=$USER->sesskey", get_string("changessaved"), 1);
+            redirect("enrol.php?sesskey=".sesskey(), get_string("changessaved"), 1);
         }
     } else {
         $frm = $CFG;
diff --git a/admin/modules.php b/admin/modules.php
index ba2b5addcc3..e8d5099b2d7 100644
--- a/admin/modules.php
+++ b/admin/modules.php
@@ -78,7 +78,7 @@
 
         if (!$confirm) {
             notice_yesno(get_string("moduledeleteconfirm", "", $strmodulename),
-                         "modules.php?delete=$delete&amp;confirm=1&amp;sesskey=$USER->sesskey",
+                         "modules.php?delete=$delete&amp;confirm=1&amp;sesskey=".sesskey(),
                          "modules.php");
             admin_externalpage_print_footer();
             exit;
@@ -217,7 +217,7 @@
         $count = $DB->count_records_select($module->name, "course<>0");
         if ($count>0) {
             $countlink = "<a href=\"{$CFG->wwwroot}/course/search.php?modulelist=$module->name" .
-                "&amp;sesskey={$USER->sesskey}\" title=\"$strshowmodulecourse\">$count</a>";
+                "&amp;sesskey=".sesskey()."\" title=\"$strshowmodulecourse\">$count</a>";
         }
         else {
             $countlink = "$count";
diff --git a/admin/user.php b/admin/user.php
index b991866f799..10325bd4465 100644
--- a/admin/user.php
+++ b/admin/user.php
@@ -261,7 +261,7 @@
                 $deletebutton = get_string($accessctrl, 'mnet');
                 if (has_capability('moodle/user:delete', $sitecontext)) {
                     // TODO: this should be under a separate capability
-                    $deletebutton .= " (<a href=\"?acl={$user->id}&amp;accessctrl=$changeaccessto&amp;sesskey={$USER->sesskey}\">"
+                    $deletebutton .= " (<a href=\"?acl={$user->id}&amp;accessctrl=$changeaccessto&amp;sesskey=".sesskey()."\">"
                             . get_string($changeaccessto, 'mnet') . " access</a>)";
                 }
                 // mnet info in edit column