diff --git a/src/synch/async.rs b/src/synch/async.rs
index bd78bace6f..6cf3352f37 100644
--- a/src/synch/async.rs
+++ b/src/synch/async.rs
@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 use core::cell::UnsafeCell;
 use core::future;
 use core::mem::MaybeUninit;
@@ -105,13 +107,13 @@ impl<T> AsyncInterruptMutex<T> {
 
 impl<'a, T: ?Sized> Deref for AsyncInterruptMutexGuard<'a, T> {
 	type Target = T;
-	fn deref<'b>(&'b self) -> &'b T {
+	fn deref(&self) -> &T {
 		&*self.data
 	}
 }
 
 impl<'a, T: ?Sized> DerefMut for AsyncInterruptMutexGuard<'a, T> {
-	fn deref_mut<'b>(&'b mut self) -> &'b mut T {
+	fn deref_mut(&mut self) -> &mut T {
 		&mut *self.data
 	}
 }