diff --git a/main/dropbox/dropbox_submit.php b/main/dropbox/dropbox_submit.php
index 8bcc8ef463..511ba88e41 100755
--- a/main/dropbox/dropbox_submit.php
+++ b/main/dropbox/dropbox_submit.php
@@ -246,7 +246,7 @@ if (isset($_GET['mailingIndex'])) { // examine or send
 		$var = api_strtoupper($nameParts[2]);  // the variable part of the name
 		$course_user = Database::get_main_table(TABLE_MAIN_COURSE_USER);
 		$sel = "SELECT u.user_id, u.lastname, u.firstname, cu.status
-				FROM `".$_configuration['main_database']."`.`user` u
+				FROM ".$_configuration['main_database'].".user u
 				LEFT JOIN $course_user cu
 				ON cu.user_id = u.user_id AND cu.relation_type<>".COURSE_RELATION_TYPE_RRHH." AND cu.course_code = '".$_course['sysCode']."'";
 		$sel .= " WHERE u.".dropbox_cnf("mailingWhere".$var)." = '";
@@ -361,7 +361,7 @@ if (isset($_GET['mailingIndex'])) { // examine or send
 			$course_user = Database::get_main_table(TABLE_MAIN_COURSE_USER);
 			$sql = "SELECT u.lastname, u.firstname
 					FROM $course_user cu
-					LEFT JOIN  `".$_configuration['main_database']."`.`user` u
+					LEFT JOIN  ".$_configuration['main_database'].".user u
 					ON cu.user_id = u.user_id AND cu.course_code = '".$_course['sysCode']."'
 					WHERE cu.status = 5
 					AND u.user_id NOT IN ('" . implode("', '" , $students) . "')";