diff --git a/css/style.css b/css/style.css
index 629d45209..5ae450eb3 100644
--- a/css/style.css
+++ b/css/style.css
@@ -202,6 +202,18 @@ button:hover {
 	min-height: initial;
 }
 
+#stack-add input:invalid {
+	box-shadow: none;
+}
+
+#stack-add input:-moz-submit-invalid {
+	box-shadow: none;
+}
+
+#stack-add input:-moz-ui-invalid {
+	box-shadow:none;
+}
+
 #stack-add button {
 	display: table-cell;
     vertical-align: middle;