diff --git a/library/stdarch/crates/core_arch/src/lib.rs b/library/stdarch/crates/core_arch/src/lib.rs
index 11377c5ca04b..068bce1b75f7 100644
--- a/library/stdarch/crates/core_arch/src/lib.rs
+++ b/library/stdarch/crates/core_arch/src/lib.rs
@@ -36,8 +36,7 @@
     asm_experimental_arch,
     sha512_sm_x86,
     x86_amx_intrinsics,
-    f16,
-    rustc_allow_const_fn_unstable
+    f16
 )]
 #![cfg_attr(test, feature(test, abi_vectorcall, stdarch_internal))]
 #![deny(clippy::missing_inline_in_public_items)]