diff --git a/htdocs/compta/facture/class/facture.class.php b/htdocs/compta/facture/class/facture.class.php
index fbba20208de..cc3d4200912 100644
--- a/htdocs/compta/facture/class/facture.class.php
+++ b/htdocs/compta/facture/class/facture.class.php
@@ -2094,8 +2094,8 @@ class Facture extends CommonInvoice
 		if (empty($txlocaltax2)) $txlocaltax2=0;
 		if (empty($fk_parent_line) || $fk_parent_line < 0) $fk_parent_line=0;
 		if (empty($fk_prev_id)) $fk_prev_id = 'null';
-		if (is_null($situation_percent) || $situation_percent > 100) $situation_percent = 100;
-
+		if (! isset($situation_percent) || $situation_percent > 100 || (string) $situation_percent == '') $situation_percent = 100;
+		    
 		$remise_percent=price2num($remise_percent);
 		$qty=price2num($qty);
 		$pu_ht=price2num($pu_ht);
@@ -2282,7 +2282,7 @@ class Facture extends CommonInvoice
 			if (empty($qty)) $qty=0;
 			if (empty($fk_parent_line) || $fk_parent_line < 0) $fk_parent_line=0;
 			if (empty($special_code) || $special_code == 3) $special_code=0;
-			if ($situation_percent > 100 || is_null($situation_percent) || $situation_percent == "") $situation_percent = 100;
+			if (! isset($situation_percent) || $situation_percent > 100 || (string) $situation_percent == '') $situation_percent = 100;
 
 			$remise_percent	= price2num($remise_percent);
 			$qty			= price2num($qty);
@@ -3881,7 +3881,7 @@ class FactureLigne extends CommonInvoiceLine
 		if (empty($this->special_code)) $this->special_code=0;
 		if (empty($this->fk_parent_line)) $this->fk_parent_line=0;
 		if (empty($this->fk_prev_id)) $this->fk_prev_id = 'null';
-		if (empty($this->situation_percent)) $this->situation_percent = 100;
+		if (! isset($this->situation_percent) || $this->situation_percent > 100 || (string) $this->situation_percent == '') $this->situation_percent = 100;
 
 		if (empty($this->pa_ht)) $this->pa_ht=0;
 
@@ -4077,9 +4077,9 @@ class FactureLigne extends CommonInvoiceLine
 		if (empty($this->special_code)) $this->special_code=0;
 		if (empty($this->product_type)) $this->product_type=0;
 		if (empty($this->fk_parent_line)) $this->fk_parent_line=0;
-		if (is_null($this->situation_percent)) $this->situation_percent=100;
+		if (! isset($this->situation_percent) || $this->situation_percent > 100 || (string) $this->situation_percent == '') $this->situation_percent = 100;
 		if (empty($this->pa_ht)) $this->pa_ht=0;
-		
+
 		// Check parameters
 		if ($this->product_type < 0) return -1;