diff --git a/enrol/locallib.php b/enrol/locallib.php
index ea3d8e85509..2d918da0e54 100644
--- a/enrol/locallib.php
+++ b/enrol/locallib.php
@@ -171,13 +171,12 @@ class course_enrolment_manager {
             $sqltotal = "SELECT COUNT(DISTINCT u.id)
                            FROM {user} u
                            JOIN {user_enrolments} ue ON (ue.userid = u.id  AND ue.enrolid $instancessql)
-                           JOIN {enrol} e ON (e.id = ue.enrolid)
-                      LEFT JOIN {groups_members} gm ON u.id = gm.userid AND gm.groupid IN (
-                               SELECT g.id
-                                 FROM {groups} g
-                                WHERE g.courseid = e.courseid
-                              )
-                          WHERE $filtersql";
+                           JOIN {enrol} e ON (e.id = ue.enrolid)";
+            if ($this->groupfilter) {
+                $sqltotal .= " LEFT JOIN ({groups_members} gm JOIN {groups} g ON (g.id = gm.groupid))
+                                         ON (u.id = gm.userid AND g.courseid = e.courseid)";
+            }
+            $sqltotal .= "WHERE $filtersql";
             $this->totalusers = (int)$DB->count_records_sql($sqltotal, $params);
         }
         return $this->totalusers;
@@ -245,13 +244,12 @@ class course_enrolment_manager {
                       FROM {user} u
                       JOIN {user_enrolments} ue ON (ue.userid = u.id  AND ue.enrolid $instancessql)
                       JOIN {enrol} e ON (e.id = ue.enrolid)
-                 LEFT JOIN {user_lastaccess} ul ON (ul.courseid = e.courseid AND ul.userid = u.id)
-                 LEFT JOIN {groups_members} gm ON u.id = gm.userid AND gm.groupid IN (
-                               SELECT g.id
-                                 FROM {groups} g
-                                WHERE g.courseid = e.courseid
-                           )
-                     WHERE $filtersql
+                 LEFT JOIN {user_lastaccess} ul ON (ul.courseid = e.courseid AND ul.userid = u.id)";
+            if ($this->groupfilter) {
+                $sql .= " LEFT JOIN ({groups_members} gm JOIN {groups} g ON (g.id = gm.groupid))
+                                    ON (u.id = gm.userid AND g.courseid = e.courseid)";
+            }
+            $sql .= "WHERE $filtersql
                   ORDER BY $sort $direction";
             $this->users[$key] = $DB->get_records_sql($sql, $params, $page*$perpage, $perpage);
         }