diff --git a/include/phone.int.inc b/include/phone.int.inc
index 68db303..b9854ee 100644
--- a/include/phone.int.inc
+++ b/include/phone.int.inc
@@ -24,6 +24,13 @@ function valid_int_phone_number($phonenumber) {
     return FALSE;
   }
   $phonenumber = _normalize_country_code($phonenumber);
+
+  // Remove Extention
+  if ($extensionpos = strpos($phonenumber, 'x')) {
+    $extension = drupal_substr($phonenumber, $extensionpos);
+    $phonenumber = drupal_substr($phonenumber, 0, $extensionpos);
+  }
+
   $base_phonenumber = str_replace(array('.', '(', ')', '[', ']', '-', '+', ' '), '', $phonenumber);
   if (!isset($field['phone_int_max_length'])) {
     $field['phone_int_max_length'] = 15;