diff --git a/docs/runtime/ffi.mdx b/docs/runtime/ffi.mdx
index 002765a7b2..d64e3e7dbe 100644
--- a/docs/runtime/ffi.mdx
+++ b/docs/runtime/ffi.mdx
@@ -358,6 +358,8 @@ Bun represents [pointers](<https://en.wikipedia.org/wiki/Pointer_(computer_progr
 
 **Why not `BigInt`?** `BigInt` is slower. JavaScript engines allocate a separate `BigInt` which means they can't fit into a regular JavaScript value. If you pass a `BigInt` to a function, it will be converted to a `number`
 
+**Windows Note**: The Windows API type HANDLE does not represent a virtual address, and using `ptr` for it will *not* work as expected. Use `u64` to safely represent HANDLE values.
+
 </Accordion>
 
 To convert from a `TypedArray` to a pointer: