diff --git a/htdocs/core/class/commondocgenerator.class.php b/htdocs/core/class/commondocgenerator.class.php
index 82012400f68..076a9682ff5 100644
--- a/htdocs/core/class/commondocgenerator.class.php
+++ b/htdocs/core/class/commondocgenerator.class.php
@@ -651,7 +651,7 @@ abstract class CommonDocGenerator
 		);
 
 		// Units
-		if (!empty($conf->global->PRODUCT_USE_UNITS)) {
+		if (getDolGlobalInt('PRODUCT_USE_UNITS')) {
 			  $resarray['line_unit'] = $outputlangs->trans($line->getLabelOfUnit('long'));
 			  $resarray['line_unit_short'] = $outputlangs->trans($line->getLabelOfUnit('short'));
 		}