diff --git a/inc/field/dropdownfield.class.php b/inc/field/dropdownfield.class.php
index d6dc4251d..a4ce6a0a8 100644
--- a/inc/field/dropdownfield.class.php
+++ b/inc/field/dropdownfield.class.php
@@ -41,6 +41,7 @@
 use DBUtils;
 use Document;
 use Dropdown;
+use CommonDBTM;
 use CommonITILActor;
 use CommonITILObject;
 use CommonTreeDropdown;