diff --git a/library/std/src/sys/pal/unix/fs.rs b/library/std/src/sys/pal/unix/fs.rs
index d2006dfc12b55..32cdd13fbebda 100644
--- a/library/std/src/sys/pal/unix/fs.rs
+++ b/library/std/src/sys/pal/unix/fs.rs
@@ -860,6 +860,7 @@ impl Drop for Dir {
             target_os = "hurd",
             target_os = "espidf",
             target_os = "fuchsia",
+            target_os = "horizon",
         )))]
         {
             let fd = unsafe { libc::dirfd(self.0) };