diff --git a/controllers/BaseApiController.php b/controllers/BaseApiController.php
index e9c2d82c..6b249e24 100644
--- a/controllers/BaseApiController.php
+++ b/controllers/BaseApiController.php
@@ -10,7 +10,7 @@ class BaseApiController extends BaseController
 
 	const PATTERN_OPERATOR = '!?(=|~|<|>|(>=)|(<=)|(§))';
 
-	const PATTERN_VALUE = '[A-Za-z\x{0400}-\x{04FF}_0-9.$#^|-]+';
+	const PATTERN_VALUE = '[A-Za-z\p{L}\p{M}*_0-9.$#^|-]+';
 
 	protected $OpenApiSpec = null;