diff --git a/locallib.php b/locallib.php
index 7ac157d..b27aa51 100644
--- a/locallib.php
+++ b/locallib.php
@@ -458,7 +458,7 @@ function attendance_can_student_mark($sess, $log = true) {
             $record = $DB->get_record_select('attendance_log', $sql, $params);
         } else {
             // Assume ATTENDANCE_SHAREDIP_FORCED.
-            $sql = 'sessionid = ? AND studentid <> ? ipaddress = ?';
+            $sql = 'sessionid = ? AND studentid <> ? AND ipaddress = ?';
             $params = array($sess->id, $USER->id, getremoteaddr());
             $record = $DB->get_record_select('attendance_log', $sql, $params);
         }