diff --git a/htdocs/margin/tabs/thirdpartyMargins.php b/htdocs/margin/tabs/thirdpartyMargins.php
index cc7a5fb1c75..144246f154a 100644
--- a/htdocs/margin/tabs/thirdpartyMargins.php
+++ b/htdocs/margin/tabs/thirdpartyMargins.php
@@ -128,10 +128,10 @@ if ($socid > 0)
 
 		$sql = "SELECT distinct s.nom, s.rowid as socid, s.code_client,";
 		$sql.= " f.rowid as facid, f.facnumber, f.total as total_ht,";
-		$sql.= " f.datef, f.paye, f.fk_statut as statut,";
-		$sql.= " sum(d.total_ht) as selling_price,";
-		$sql.= " ".$db->ifsql('f.type =2','sum(d.qty * d.buy_price_ht *-1)','sum(d.qty * d.buy_price_ht)')." as buying_price,";
-        $sql.= " ".$db->ifsql('f.type =2','sum(-1 * (abs(d.total_ht) - (d.buy_price_ht * d.qty)))','sum(d.total_ht - (d.buy_price_ht * d.qty))')." as marge";
+		$sql.= " f.datef, f.paye, f.fk_statut as statut, f.type,";
+		$sql.= " sum(d.total_ht) as selling_price,";						// may be negative or positive
+		$sql.= " sum(d.qty * d.buy_price_ht) as buying_price,";				// always positive
+        $sql.= " sum(abs(d.total_ht) - (d.buy_price_ht * d.qty)) as marge";	// always positive
 		$sql.= " FROM ".MAIN_DB_PREFIX."societe as s";
 		$sql.= ", ".MAIN_DB_PREFIX."facture as f";
 		$sql.= ", ".MAIN_DB_PREFIX."facturedet as d";
@@ -140,9 +140,9 @@ if ($socid > 0)
 		$sql.= " AND s.entity = ".$conf->entity;
 		$sql.= " AND d.fk_facture = f.rowid";
 		$sql.= " AND f.fk_soc = $socid";
-		$sql .= " AND d.buy_price_ht IS NOT NULL";
+		$sql.= " AND d.buy_price_ht IS NOT NULL";
 		if (isset($conf->global->ForceBuyingPriceIfNull) && $conf->global->ForceBuyingPriceIfNull == 1) $sql .= " AND d.buy_price_ht <> 0";
-		$sql.= " GROUP BY s.nom, s.rowid, s.code_client, f.rowid, f.facnumber, f.total, f.datef, f.paye, f.fk_statut";
+		$sql.= " GROUP BY s.nom, s.rowid, s.code_client, f.rowid, f.facnumber, f.total, f.datef, f.paye, f.fk_statut, f.type";
 		$sql.= " ORDER BY ".$sortfield." ".$sortorder;
 		// TODO: calculate total to display then restore pagination
 		//$sql.= $db->plimit($conf->liste_limit +1, $offset);
@@ -153,7 +153,7 @@ if ($socid > 0)
 		{
 			$num = $db->num_rows($result);
 
-			print_barre_liste($langs->trans("MarginDetails"),$page,$_SERVER["PHP_SELF"],"&amp;socid=$societe->id",$sortfield,$sortorder,'',0,0,'');
+			print_barre_liste($langs->trans("MarginDetails"),$page,$_SERVER["PHP_SELF"],"&amp;socid=".$societe->id,$sortfield,$sortorder,'',0,0,'');
 
 			$i = 0;
 			print "<table class=\"noborder\" width=\"100%\">";
@@ -183,16 +183,8 @@ if ($socid > 0)
 				{
 					$objp = $db->fetch_object($result);
 
-					if ($objp->marge < 0)
-					{
-						$marginRate = ($objp->buying_price != 0)?-1*(100 * $objp->marge / $objp->buying_price):'' ;
-						$markRate = ($objp->selling_price != 0)?-1*(100 * $objp->marge / $objp->selling_price):'' ;
-					}
-					else
-					{
-						$marginRate = ($objp->buying_price != 0)?(100 * $objp->marge / $objp->buying_price):'' ;
-						$markRate = ($objp->selling_price != 0)?(100 * $objp->marge / $objp->selling_price):'' ;
-					}
+					$marginRate = ($objp->buying_price != 0)?(100 * $objp->marge / $objp->buying_price):'' ;
+					$markRate = ($objp->selling_price != 0)?(100 * $objp->marge / $objp->selling_price):'' ;
 
 					$var=!$var;
 
@@ -205,7 +197,7 @@ if ($socid > 0)
 					print "<td align=\"center\">";
 					print dol_print_date($db->jdate($objp->datef),'day')."</td>";
 					print "<td align=\"right\">".price($objp->selling_price, null, null, null, null, $rounding)."</td>\n";
-					print "<td align=\"right\">".price($objp->buying_price, null, null, null, null, $rounding)."</td>\n";
+					print "<td align=\"right\">".price(($objp->type == 2 ? -1 : 1) * $objp->buying_price, null, null, null, null, $rounding)."</td>\n";
 					print "<td align=\"right\">".price($objp->marge, null, null, null, null, $rounding)."</td>\n";
 					if (! empty($conf->global->DISPLAY_MARGIN_RATES))
 						print "<td align=\"right\">".(($marginRate === '')?'n/a':price($marginRate, null, null, null, null, $rounding)."%")."</td>\n";
@@ -214,7 +206,7 @@ if ($socid > 0)
 					print '<td align="right">'.$invoicestatic->LibStatut($objp->paye,$objp->statut,5).'</td>';
 					print "</tr>\n";
 					$i++;
-					$cumul_achat += $objp->buying_price;
+					$cumul_achat += (($objp->type == 2 ? -1 : 1) * $objp->buying_price);
 					$cumul_vente += $objp->selling_price;
 				}
 			}