diff --git a/src/memoryview.hh b/src/memoryview.hh
index d8e509d5..238ee386 100644
--- a/src/memoryview.hh
+++ b/src/memoryview.hh
@@ -1,6 +1,7 @@
 #ifndef memoryview_hh_INCLUDED
 #define memoryview_hh_INCLUDED
 
+#include <cstddef>
 #include <vector>
 #include <initializer_list>