diff --git a/htdocs/core/tpl/objectline_edit.tpl.php b/htdocs/core/tpl/objectline_edit.tpl.php
index 98c5a03c5da..bc79a403002 100644
--- a/htdocs/core/tpl/objectline_edit.tpl.php
+++ b/htdocs/core/tpl/objectline_edit.tpl.php
@@ -257,8 +257,14 @@ $coldisplay=-1; // We remove first td
 
 jQuery(document).ready(function()
 {
-	jQuery("#price_ht").keyup(function() { jQuery("#price_ttc").val(''); });
-	jQuery("#price_ttc").keyup(function() { jQuery("#price_ht").val(''); });
+	jQuery("#price_ht").keyup(function(event) {
+		// console.log(event.which);		// discard event tag and arrows
+		if (event.which != 9 && (event.which < 37 ||event.which > 40) && jQuery("#price_ht").val() != '') jQuery("#price_ttc").val(''); 
+		});
+	jQuery("#price_ttc").keyup(function(event) {
+		// console.log(event.which);		// discard event tag and arrows
+		if (event.which != 9 && (event.which < 37 || event.which > 40) && jQuery("#price_ttc").val() != '') jQuery("#price_ht").val(''); 
+		});
 
     <?php
     if (! empty($conf->margin->enabled))