diff --git a/htdocs/core/lib/ajax.lib.php b/htdocs/core/lib/ajax.lib.php
index a1a211fac91..2993197b660 100644
--- a/htdocs/core/lib/ajax.lib.php
+++ b/htdocs/core/lib/ajax.lib.php
@@ -139,6 +139,11 @@ function ajax_autocompleter($selected, $htmlname, $url, $urloption='', $minLengt
     						}
     						// Update an input
     						if (ui.item.update) {
+    							// clear old data before update
+    							$.each(ui.item.update, function(key, value) {
+    								$("#" + key).val("");
+    							});
+    							// update fields
     							$.each(ui.item.update, function(key, value) {
     								$("#" + key).val(value).trigger("change");
     							});
diff --git a/htdocs/core/tpl/objectline_add.tpl.php b/htdocs/core/tpl/objectline_add.tpl.php
index d86400b8fbc..f8121ad93f5 100644
--- a/htdocs/core/tpl/objectline_add.tpl.php
+++ b/htdocs/core/tpl/objectline_add.tpl.php
@@ -385,9 +385,9 @@ $(document).ready(function() {
 			$('#price_ttc').attr('disabled','disabled');
 			$('#price_ttc').val('');
 		} else {
-			if ($('#idprod').val() == 0) {
-				$('#price_ttc').removeAttr('disabled');
-			}
+			// Enable excl.VAT field
+			$('#price_ttc').removeAttr('disabled');
+			// Update prices fields
 			if ($('#price_base_type').val() == 'HT') {
 				update_price('price_ht', 'price_ttc');
 			} else if ($('#price_base_type').val() == 'TTC') {