diff --git a/src/common/hash.h b/src/common/hash.h
index 188d1c5554..ee2560dadb 100644
--- a/src/common/hash.h
+++ b/src/common/hash.h
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <cstddef>
 #include "common/common_types.h"
 
 namespace Common {