diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 40c1f549b0ba..f08583fa39c9 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -68,6 +68,7 @@ pub(crate) fn as_raw(&self) -> *mut bindings::device {
     }
 
     /// Returns a reference to the parent device, if any.
+    #[cfg_attr(not(CONFIG_AUXILIARY_BUS), expect(dead_code))]
     pub(crate) fn parent(&self) -> Option<&Self> {
         // SAFETY:
         // - By the type invariant `self.as_raw()` is always valid.