diff --git a/src/lib/utility/types.h b/src/lib/utility/types.h
index e853233c..754161c2 100644
--- a/src/lib/utility/types.h
+++ b/src/lib/utility/types.h
@@ -1,6 +1,8 @@
 #ifndef TYPES_H
 #define TYPES_H
 
+#include <cstddef>
+
 typedef size_t Id;
 
 typedef unsigned int uint;