diff --git a/user/lib.php b/user/lib.php
index f7008b5fe60..e42ae4113eb 100644
--- a/user/lib.php
+++ b/user/lib.php
@@ -1505,7 +1505,7 @@ function user_get_course_lastaccess_sql($accesssince = null, $tableprefix = 'ul'
     if ($accesssince == -1) { // Never.
         return $tableprefix . '.timeaccess = 0';
     } else {
-        return $tableprefix . '.timeaccess != 0 AND ul.timeaccess < ' . $accesssince;
+        return $tableprefix . '.timeaccess != 0 AND ' . $tableprefix . '.timeaccess < ' . $accesssince;
     }
 }
 
@@ -1524,7 +1524,7 @@ function user_get_user_lastaccess_sql($accesssince = null, $tableprefix = 'u') {
     if ($accesssince == -1) { // Never.
         return $tableprefix . '.lastaccess = 0';
     } else {
-        return $tableprefix . '.lastaccess != 0 AND u.lastaccess < ' . $accesssince;
+        return $tableprefix . '.lastaccess != 0 AND ' . $tableprefix . '.lastaccess < ' . $accesssince;
     }
 }