diff --git a/Providers/MMFRestrictedCustomersServiceProvider.php b/Providers/MMFRestrictedCustomersServiceProvider.php
index 7bd8bdb..ebf9159 100644
--- a/Providers/MMFRestrictedCustomersServiceProvider.php
+++ b/Providers/MMFRestrictedCustomersServiceProvider.php
@@ -44,7 +44,7 @@ class MMFRestrictedCustomersServiceProvider extends ServiceProvider {
 				// Get IDs of mailboxes the current user is allowed to access.
 				$mailboxes = $user->mailboxesIdsCanView();
 				// Restrict the query to the Customers the current user is allowed to access.
-				$query_customers->whereIn('customers.mailbox_id', $mailbox_ids);
+				$query_customers->whereIn('customers.mailbox_id', $mailboxes);
 			}
 			return $query_customers;
 		});