diff --git a/lib/KorAP/XML/Annotation/Base.pm b/lib/KorAP/XML/Annotation/Base.pm
index d38c521..0867362 100644
--- a/lib/KorAP/XML/Annotation/Base.pm
+++ b/lib/KorAP/XML/Annotation/Base.pm
@@ -1,6 +1,7 @@
 package KorAP::XML::Annotation::Base;
 use strict;
 use warnings;
+use feature ':5.10';
 
 # Importing method
 sub import {