diff --git a/library/alloc/tests/fmt.rs b/library/alloc/tests/fmt.rs
index c13074c53b73d..91d2a2a152753 100644
--- a/library/alloc/tests/fmt.rs
+++ b/library/alloc/tests/fmt.rs
@@ -1,6 +1,6 @@
 #![deny(warnings)]
 // FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
-#![allow(static_mut_refs)]
+#![allow(static_mut_refs, redundant_transmutation)]
 
 use std::cell::RefCell;
 use std::fmt::{self, Write};