diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index b47cf6d965d..d5fd1f13db5 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -10167,7 +10167,7 @@ class ByteBuffer : public AllStatic {
 class Pointer : public Instance {
  public:
   static PointerPtr New(const AbstractType& type_arg,
-                        uword native_address,
+                        size_t native_address,
                         Heap::Space space = Heap::kNew);
 
   static intptr_t InstanceSize() {