diff --git a/EqSat/include/Luau/Id.h b/EqSat/include/Luau/Id.h
index 13de424f..c56a6ab6 100644
--- a/EqSat/include/Luau/Id.h
+++ b/EqSat/include/Luau/Id.h
@@ -1,6 +1,7 @@
 // This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
 #pragma once
 
+#include <cstddef>
 #include <functional>
 
 namespace Luau::EqSat
diff --git a/EqSat/include/Luau/Slice.h b/EqSat/include/Luau/Slice.h
index 3d3c1b18..886f0c3e 100644
--- a/EqSat/include/Luau/Slice.h
+++ b/EqSat/include/Luau/Slice.h
@@ -4,6 +4,7 @@
 #include "Luau/Common.h"
 
 #include <array>
+#include <cstddef>
 
 namespace Luau::EqSat
 {