diff --git a/htdocs/bom/class/bom.class.php b/htdocs/bom/class/bom.class.php
index ac73ab58475..c57a5816517 100644
--- a/htdocs/bom/class/bom.class.php
+++ b/htdocs/bom/class/bom.class.php
@@ -1128,7 +1128,7 @@ class BOM extends CommonObject
 					}
 				} else {
 					//Convert qty to hour
-					$unit = measuringUnitString($line->fk_unit);
+					$unit = measuringUnitString($line->fk_unit, '', '', 1);
 					$qty = convertDurationtoHour($line->qty, $unit);
 
 					if ($conf->workstation->enabled) {