diff --git a/htdocs/salaries/card.php b/htdocs/salaries/card.php
index b0abeeb134a..9d030815f8b 100755
--- a/htdocs/salaries/card.php
+++ b/htdocs/salaries/card.php
@@ -263,7 +263,10 @@ if ($action == 'add' && empty($cancel)) {
 		$db->begin();
 
 		$ret = $object->create($user);
-		if ($ret < 0) $error++;
+		if ($ret < 0) {
+			var_dump($ret);
+			$error++;
+		}
 		if (!empty($auto_create_paiement) && !$error) {
 			// Create a line of payments
 			$paiement = new PaymentSalary($db);
@@ -562,10 +565,12 @@ if ($action == 'create') {
 	print '<td class="tdtop"><textarea name="note" wrap="soft" cols="60" rows="'.ROWS_3.'">'.GETPOST('note', 'restricthtml').'</textarea></td>';
 	print '</tr>';
 
+
 	print '<tr><td colspan="2"><hr></td></tr>';
 
+
 	// Auto create payment
-	print '<tr><td>'.$langs->trans('AutomaticCreationPayment').'</td>';
+	print '<tr><td><label for="auto_create_paiement">'.$langs->trans('AutomaticCreationPayment').'</label></td>';
 	print '<td><input id="auto_create_paiement" name="auto_create_paiement" type="checkbox" ' . (empty($auto_create_paiement) ? '' : 'checked="checked"') . ' value="1"></td></tr>'."\n";	// Date payment
 
 	// Bank
@@ -997,14 +1002,14 @@ if ($id) {
 
 	print '<div class="clearboth"></div>';
 
+	print dol_get_fiche_end();
 
 	if ($action == 'edit') {
 		print $form->buttonsSaveCancel();
 		print "</form>";
 	}
 
-	print dol_get_fiche_end();
-
+	$resteapayer = price2num($resteapayer, 'MT');
 
 	/*
 	 * Action bar
@@ -1023,17 +1028,13 @@ if ($id) {
 		}
 
 		// Emit payment
-		if ($object->paye == 0 && ((price2num($object->amount) < 0 && price2num($resteapayer, 'MT') < 0) || (price2num($object->amount) > 0 && price2num($resteapayer, 'MT') > 0)) && $user->rights->salaries->write) {
+		if ($object->paye == 0 && ((price2num($object->amount) < 0 && $resteapayer < 0) || (price2num($object->amount) > 0 && $resteapayer > 0)) && $user->rights->salaries->write) {
 			print '<div class="inline-block divButAction"><a class="butAction" href="'.DOL_URL_ROOT."/salaries/paiement_salary.php?id=".$object->id.'&action=create&token='.newToken().'">'.$langs->trans("DoPayment")."</a></div>";
 		}
 
 		// Classify 'paid'
-		if ($object->paye == 0
-			&& (
-				(round($resteapayer) <= 0 && $object->amount > 0)
-				|| (round($resteapayer) >= 0 && $object->amount < 0)
-			)
-			&& $user->rights->salaries->write) {
+		// If at least one payment was already done ($object->amount - $resteapayer >  0) or if amount is negative, we allow to classify as paid.
+		if ($object->paye == 0 && ((($object->amount - $resteapayer) > 0 && $object->amount > 0) || ($object->amount <= 0)) && $user->rights->salaries->write) {
 			print "<div class=\"inline-block divButAction\"><a class=\"butAction\" href=\"".DOL_URL_ROOT."/salaries/card.php?id=".$object->id.'&action=paid&token='.newToken().'">'.$langs->trans("ClassifyPaid")."</a></div>";
 		}
 
diff --git a/htdocs/salaries/class/salary.class.php b/htdocs/salaries/class/salary.class.php
index 454a94bcf1f..2acc2117297 100644
--- a/htdocs/salaries/class/salary.class.php
+++ b/htdocs/salaries/class/salary.class.php
@@ -367,7 +367,7 @@ class Salary extends CommonObject
 			$this->error = $langs->trans("ErrorFieldRequired", $langs->transnoentities("Employee"));
 			return -4;
 		}
-		if ($this->amount < 0 || $this->amount == '') {
+		if ($this->amount == '') {
 			$this->error = $langs->trans("ErrorFieldRequired", $langs->transnoentities("Amount"));
 			return -5;
 		}