diff --git a/addressbook/inc/class.addressbook_bo.inc.php b/addressbook/inc/class.addressbook_bo.inc.php
index 4f21de5ca8..91001a6289 100755
--- a/addressbook/inc/class.addressbook_bo.inc.php
+++ b/addressbook/inc/class.addressbook_bo.inc.php
@@ -504,6 +504,12 @@ class addressbook_bo extends addressbook_so
 					{
 						$fields_to_update[$field_name] = $field_value = null;
 					}
+					// check for valid birthday date
+					if ($field_name == 'bday' && $field_value != null &&
+						!preg_match('/^(18|19|20)\d{2}-(0[1-9]|1[0-2])-(0[1-9]|[12][0-9]|3[01])$/',$field_value))
+					{
+						$fields_to_update[$field_name] = $field_value = null;
+					}
 				}
 
 				if(count($fields_to_update) > 0)