diff --git a/local/recipes/drivers/redox-driver-sys/source/src/pci.rs b/local/recipes/drivers/redox-driver-sys/source/src/pci.rs
index 362aaa27f7..7c6f2f1650 100644
--- a/local/recipes/drivers/redox-driver-sys/source/src/pci.rs
+++ b/local/recipes/drivers/redox-driver-sys/source/src/pci.rs
@@ -1,4 +1,8 @@
 use std::io::{Read, Seek, SeekFrom, Write};
+// `Once` backs the per-thread IOPL guard below (Redox-only). Gated to match the
+// `#[cfg(target_os = "redox")]` thread_local so non-Redox builds don't warn on
+// an unused import.
+#[cfg(target_os = "redox")]
 use std::sync::Once;
 
 use crate::{DriverError, Result};