diff --git a/htdocs/accountancy/bookkeeping/card.php b/htdocs/accountancy/bookkeeping/card.php
index b3367ad1b8e..fb63e503423 100644
--- a/htdocs/accountancy/bookkeeping/card.php
+++ b/htdocs/accountancy/bookkeeping/card.php
@@ -171,8 +171,8 @@ elseif ($action == "add") {
 		$object->doc_ref = GETPOST('doc_ref', 'alpha');
 		$object->code_journal = $journal_code;
 		$object->journal_label = $journal_label;
-		$object->fk_doc = GETPOST('fk_doc', 'int');
-		$object->fk_docdet = GETPOST('fk_docdet', 'int');
+		$object->fk_doc = (int) GETPOST('fk_doc', 'int');
+		$object->fk_docdet = (int) GETPOST('fk_docdet', 'int');
 
 		if (floatval($debit) != 0.0) {
 			$object->montant = $debit;