diff --git a/addons/web/static/src/js/view_form.js b/addons/web/static/src/js/view_form.js
index e761173e042..290af47c04c 100644
--- a/addons/web/static/src/js/view_form.js
+++ b/addons/web/static/src/js/view_form.js
@@ -790,6 +790,11 @@ openerp.web.form.Widget = openerp.web.Widget.extend(/** @lends openerp.web.form.
         return QWeb.render(template, { "widget": this });
     },
     do_attach_tooltip: function(widget, trigger, options) {
+        if ($.browser.mozilla && parseInt($.browser.version.split('.')[0], 10) < 2) {
+            // Unknown bug in old version of firefox :
+            // input type=text onchange event not fired when tootip is shown
+            return;
+        }
         widget = widget || this;
         trigger = trigger || this.$element;
         options = _.extend({