diff --git a/htdocs/core/class/commondocgenerator.class.php b/htdocs/core/class/commondocgenerator.class.php
index 972275059bb..0a78897adcc 100644
--- a/htdocs/core/class/commondocgenerator.class.php
+++ b/htdocs/core/class/commondocgenerator.class.php
@@ -509,11 +509,14 @@ abstract class CommonDocGenerator
 		    'line_multicurrency_total_ht_locale' => price($line->multicurrency_total_ht, 0, $outputlangs),
 		    'line_multicurrency_total_tva_locale' => price($line->multicurrency_total_tva, 0, $outputlangs),
 		    'line_multicurrency_total_ttc_locale' => price($line->multicurrency_total_ttc, 0, $outputlangs),
-
-		    // Units
-		    'line_unit'=>$outputlangs->trans($line->getLabelOfUnit('long')),
-		    'line_unit_short'=>$outputlangs->trans($line->getLabelOfUnit('short')),
 		);
+		
+		    // Units
+		if ($conf->global->PRODUCT_USE_UNITS)
+		{
+		      $resarray['line_unit']=$outputlangs->trans($line->getLabelOfUnit('long')),
+		      $resarray['line_unit_short']=$outputlangs->trans($line->getLabelOfUnit('short'))
+		}
 
 		// Retrieve extrafields
 		$extrafieldkey=$line->element;