diff --git a/htdocs/supplier_proposal/class/supplier_proposal.class.php b/htdocs/supplier_proposal/class/supplier_proposal.class.php
index 6b76cf23af6..78fc1c7fd15 100644
--- a/htdocs/supplier_proposal/class/supplier_proposal.class.php
+++ b/htdocs/supplier_proposal/class/supplier_proposal.class.php
@@ -3035,7 +3035,7 @@ class SupplierProposalLine extends CommonObjectLine
 		$sql .= " ".price2num($this->localtax2_tx).",";
 		$sql .= " '".$this->db->escape($this->localtax1_type)."',";
 		$sql .= " '".$this->db->escape($this->localtax2_type)."',";
-		$sql .= " ".(!empty($this->subprice) ?price2num($this->subprice) : "null").",";
+		$sql .= " ".(!empty($this->subprice) ?price2num($this->subprice) : 0).",";
 		$sql .= " ".price2num($this->remise_percent).",";
 		$sql .= " ".(isset($this->info_bits) ? "'".$this->db->escape($this->info_bits)."'" : "null").",";
 		$sql .= " ".price2num($this->total_ht).",";