diff --git a/classes/pdf/HTMLTemplateOrderSlip.php b/classes/pdf/HTMLTemplateOrderSlip.php
index 6ce9d18d8..e03637132 100644
--- a/classes/pdf/HTMLTemplateOrderSlip.php
+++ b/classes/pdf/HTMLTemplateOrderSlip.php
@@ -170,15 +170,15 @@ class HTMLTemplateOrderSlipCore extends HTMLTemplateInvoice
 					$tax = new Tax((int)$tax_id);
 					if (!isset($total_tax_amount[$tax->rate]))
 					{
-						$tmp_tax_infos[(string)$tax->rate]['name'] = $tax->name;
-						$tmp_tax_infos[(string)$tax->rate]['total_price_tax_excl'] = $order_slip_details['amount_tax_excl'];
-						$tmp_tax_infos[(string)$tax->rate]['total_amount'] = $amount;
+						$tmp_tax_infos[$tax->rate]['name'] = $tax->name;
+						$tmp_tax_infos[$tax->rate]['total_price_tax_excl'] = $order_slip_details['amount_tax_excl'];
+						$tmp_tax_infos[$tax->rate]['total_amount'] = $amount;
 					}
 					else
 					{
 
-						$tmp_tax_infos[(string)$tax->rate]['total_price_tax_excl'] += $order_slip_details['amount_tax_excl'];
-						$tmp_tax_infos[(string)$tax->rate]['total_amount'] += $amount;
+						$tmp_tax_infos[$tax->rate]['total_price_tax_excl'] += $order_slip_details['amount_tax_excl'];
+						$tmp_tax_infos[$tax->rate]['total_amount'] += $amount;
 					}
 				}
 			} else {
@@ -198,7 +198,7 @@ class HTMLTemplateOrderSlipCore extends HTMLTemplateInvoice
 					$infos['total_amount'] += $amount;
 				}
 
-				$tmp_tax_infos[(string)$tax_rate] = $infos;
+				$tmp_tax_infos[(string)number_format($tax_rate, 3)] = $infos;
 			}
 
 		}