diff --git a/codex-rs/windows-sandbox-rs/src/proc_thread_attr.rs b/codex-rs/windows-sandbox-rs/src/proc_thread_attr.rs
index 7641bb5ed..b81469983 100644
--- a/codex-rs/windows-sandbox-rs/src/proc_thread_attr.rs
+++ b/codex-rs/windows-sandbox-rs/src/proc_thread_attr.rs
@@ -1,3 +1,4 @@
+use std::ffi::c_void;
 use std::io;
 use windows_sys::Win32::Foundation::GetLastError;
 use windows_sys::Win32::Foundation::HANDLE;
@@ -45,14 +46,13 @@ impl ProcThreadAttributeList {
 
     pub fn set_pseudoconsole(&mut self, hpc: isize) -> io::Result<()> {
         let list = self.as_mut_ptr();
-        let mut hpc_value = hpc;
         let ok = unsafe {
             UpdateProcThreadAttribute(
                 list,
                 0,
                 PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE,
-                (&mut hpc_value as *mut isize).cast(),
-                std::mem::size_of::<isize>(),
+                hpc as *mut c_void,
+                std::mem::size_of::<HANDLE>(),
                 std::ptr::null_mut(),
                 std::ptr::null_mut(),
             )