diff --git a/internal/service/default.go b/internal/service/default.go
index 9810fba..e11920b 100644
--- a/internal/service/default.go
+++ b/internal/service/default.go
@@ -10,7 +10,7 @@ const (
 )
 
 var (
-	safeInputRegex = regexp.MustCompile(`^[a-zA-Z0-9ÄÖÜäöüß,&'". -]+$`)
+	safeInputRegex = regexp.MustCompile(`^[a-zA-Z0-9ÄÖÜäöüß,&'". -?]+$`)
 )
 
 func validateString(value string, fieldName string) error {