diff -u b/includes/form.inc b/includes/form.inc
--- b/includes/form.inc
+++ b/includes/form.inc
@@ -4025,7 +4025,7 @@
 function theme_textfield($variables) {
   $element = $variables['element'];
   _form_set_class($element, array('form-text'));
-  element_set_attributes($element, array('id', 'name', 'value', 'size', 'maxlength'));
+  element_set_attributes($element, array('id', 'name', 'value', 'size', 'maxlength', 'min', 'max'));
 
   // Allow HTML input types which do not have an existing equivalent in the Form
   // API. We define them as #subtype in our form element configuration.