diff --git a/course/reset_form.php b/course/reset_form.php
index ce8b0f708b6..cb899f0d63b 100644
--- a/course/reset_form.php
+++ b/course/reset_form.php
@@ -27,6 +27,9 @@ class course_reset_form extends moodleform {
         $mform->addElement('header', 'rolesheader', get_string('roles'));
 
         $roles = get_assignable_roles(get_context_instance(CONTEXT_COURSE, $COURSE->id));
+        $roles[0] = get_string('noroles', 'role');
+        $roles = array_reverse($roles, true);
+
         $mform->addElement('select', 'unenrol_users', get_string('unenrolroleusers', 'enrol'), $roles, array('multiple' => 'multiple'));
         $mform->addElement('checkbox', 'reset_roles_overrides', get_string('deletecourseoverrides', 'role'));
         $mform->setAdvanced('reset_roles_overrides');
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 0099f60bfc9..942ab0bf92e 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -4775,12 +4775,24 @@ function reset_course_userdata($data) {
         }
 
         foreach($data->unenrol_users as $withroleid) {
-            $sql = "SELECT ue.*
-                      FROM {user_enrolments} ue
-                      JOIN {enrol} e ON (e.id = ue.enrolid AND e.courseid = :courseid)
-                      JOIN {context} c ON (c.contextlevel = :courselevel AND c.instanceid = e.courseid)
-                      JOIN {role_assignments} ra ON (ra.contextid = c.id AND ra.roleid = :roleid AND ra.userid = ue.userid)";
-            $params = array('courseid'=>$data->courseid, 'roleid'=>$withroleid, 'courselevel'=>CONTEXT_COURSE);
+            if ($withroleid) {
+                $sql = "SELECT ue.*
+                          FROM {user_enrolments} ue
+                          JOIN {enrol} e ON (e.id = ue.enrolid AND e.courseid = :courseid)
+                          JOIN {context} c ON (c.contextlevel = :courselevel AND c.instanceid = e.courseid)
+                          JOIN {role_assignments} ra ON (ra.contextid = c.id AND ra.roleid = :roleid AND ra.userid = ue.userid)";
+                $params = array('courseid'=>$data->courseid, 'roleid'=>$withroleid, 'courselevel'=>CONTEXT_COURSE);
+
+            } else {
+                // without any role assigned at course context
+                $sql = "SELECT ue.*
+                          FROM {user_enrolments} ue
+                          JOIN {enrol} e ON (e.id = ue.enrolid AND e.courseid = :courseid)
+                          JOIN {context} c ON (c.contextlevel = :courselevel AND c.instanceid = e.courseid)
+                     LEFT JOIN {role_assignments} ra ON (ra.contextid = c.id AND ra.userid = ue.userid)
+                         WHERE ra.id IS NULL";
+                $params = array('courseid'=>$data->courseid, 'courselevel'=>CONTEXT_COURSE);
+            }
 
             $rs = $DB->get_recordset_sql($sql, $params);
             foreach ($rs as $ue) {