diff --git a/lib/helpers.class.php b/lib/helpers.class.php
index 37242bf..6e5e090 100644
--- a/lib/helpers.class.php
+++ b/lib/helpers.class.php
@@ -24,7 +24,7 @@ class Helpers {
 
   // Check Search String for Valid Characters
   public static function validate_search($search) {
-    if (!preg_match("#^[a-zA-Z0-9äöüÄÖÜ _\-\.\*\?\;\(\)]+$#", $search)) {
+    if (!preg_match("#^[a-zA-Z0-9äöüÄÖÜ _\-\.\*\?\:\(\)\']+$#", $search)) {
       return false;
     } else {
       return true;