diff --git a/ydb/library/actors/core/buffer.h b/ydb/library/actors/core/buffer.h
index 95425046d690..c305d948a6af 100644
--- a/ydb/library/actors/core/buffer.h
+++ b/ydb/library/actors/core/buffer.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstddef>
 #include <limits>
 
 class TConstBuffer;