diff --git a/library/stdarch/coresimd/x86/mod.rs b/library/stdarch/coresimd/x86/mod.rs
index 44ab494d04e1..aba3d137c066 100644
--- a/library/stdarch/coresimd/x86/mod.rs
+++ b/library/stdarch/coresimd/x86/mod.rs
@@ -338,9 +338,8 @@ mod test;
 #[cfg(test)]
 pub use self::test::*;
 
-#[doc(hidden)]
 #[allow(non_camel_case_types)]
-#[stable(feature = "simd_x86", since = "1.27.0")]
+#[unstable(feature = "stdimd_internal", issue = "0")]
 pub(crate) trait m128iExt: Sized {
     fn as_m128i(self) -> __m128i;
 
@@ -392,9 +391,8 @@ impl m128iExt for __m128i {
     }
 }
 
-#[doc(hidden)]
 #[allow(non_camel_case_types)]
-#[stable(feature = "simd_x86", since = "1.27.0")]
+#[unstable(feature = "stdimd_internal", issue = "0")]
 pub(crate) trait m256iExt: Sized {
     fn as_m256i(self) -> __m256i;