diff --git a/rustc-hash/src/lib.rs b/rustc-hash/src/lib.rs
index e0715a2d743a6..d043182e0333e 100644
--- a/rustc-hash/src/lib.rs
+++ b/rustc-hash/src/lib.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 #![feature(hasher_prefixfree_extras)]
+#![allow(rustc::default_hash_types)]
 
 //! Fast, non-cryptographic hash used by rustc and Firefox.
 //!