diff --git a/htdocs/comm/propal/class/propal.class.php b/htdocs/comm/propal/class/propal.class.php
index 46f06614941..5b382a4cb62 100644
--- a/htdocs/comm/propal/class/propal.class.php
+++ b/htdocs/comm/propal/class/propal.class.php
@@ -917,8 +917,8 @@ class Propal extends CommonObject
 			$this->line->tva_tx = $txtva;
 			$this->line->localtax1_tx		= $txlocaltax1;
 			$this->line->localtax2_tx		= $txlocaltax2;
-			$this->line->localtax1_type		= $localtaxes_type[0];
-			$this->line->localtax2_type		= $localtaxes_type[2];
+			$this->line->localtax1_type 	= empty($localtaxes_type[0]) ? '' : $localtaxes_type[0];
+			$this->line->localtax2_type 	= empty($localtaxes_type[2]) ? '' : $localtaxes_type[2];
 			$this->line->remise_percent		= $remise_percent;
 			$this->line->subprice			= $pu_ht;
 			$this->line->info_bits			= $info_bits;