diff --git a/clientside_validation_fapi/clientside_validation_fapi.module b/clientside_validation_fapi/clientside_validation_fapi.module
index 0f506b6..531cce1 100644
--- a/clientside_validation_fapi/clientside_validation_fapi.module
+++ b/clientside_validation_fapi/clientside_validation_fapi.module
@@ -80,12 +80,12 @@ function _clientside_validation_set_fapi_validation($element, $rule, $params, &$
     $title = $element['#title'];
   }
   $expressions = array(
-    'fapi_validation_rule_alpha' => '/^[\p{L}]+$/uD',
-    'fapi_validation_rule_alpha_numeric' => '/^[\p{L}\p{N}]+$/uD',
+    'fapi_validation_rule_alpha' => '/^[\p{L}]*$/uD',
+    'fapi_validation_rule_alpha_numeric' => '/^[\p{L}\p{N}]*$/uD',
     'fapi_validation_rule_ipv4' => '/^([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
       . '(\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}$/',
-    'fapi_validation_rule_alpha_dash' => '/^[-\p{L}\p{N}_]+$/uD',
-    'fapi_validation_rule_digit' => '/^\d+$/',
+    'fapi_validation_rule_alpha_dash' => '/^[-\p{L}\p{N}_]*$/uD',
+    'fapi_validation_rule_digit' => '/^\d*$/',
   );
   if (strpos($message, '%field') !== FALSE) {
     $message = t($message, array('%field' => _clientside_validation_set_title($title)));