diff --git a/deps/ox/src/ox/std/anyptr.hpp b/deps/ox/src/ox/std/anyptr.hpp
index c6611318..ac11e484 100644
--- a/deps/ox/src/ox/std/anyptr.hpp
+++ b/deps/ox/src/ox/std/anyptr.hpp
@@ -1,7 +1,9 @@
 
 #pragma once
 
+#include "assert.hpp"
 #include "array.hpp"
+#include "def.hpp"
 #include "span.hpp"
 
 namespace ox {
@@ -20,6 +22,7 @@ class AnyPtr {
 			constexpr Wrap(T *pData) noexcept: data(pData) {
 			}
 			constexpr WrapBase *copyTo(ox::Span<char> s) noexcept override {
+				oxAssert(s.size() >= sizeof(Wrap), "too small buffer");
 				if (std::is_constant_evaluated()) {
 					return new Wrap(data);
 				} else {