2 files changed, 1 insertions, 9 deletions
diff --git a/compiler/rustc_builtin_macros/src/errors.rs b/compiler/rustc_builtin_macros/src/errors.rs
index b28f7d312d9..b3cc460abbf 100644
--- a/compiler/rustc_builtin_macros/src/errors.rs
+++ b/compiler/rustc_builtin_macros/src/errors.rs
@@ -188,14 +188,6 @@ mod autodiff {
     }
 
     #[derive(Diagnostic)]
-    #[diag(builtin_macros_autodiff_mode)]
-    pub(crate) struct AutoDiffInvalidMode {
-        #[primary_span]
-        pub(crate) span: Span,
-        pub(crate) mode: String,
-    }
-
-    #[derive(Diagnostic)]
     #[diag(builtin_macros_autodiff_width)]
     pub(crate) struct AutoDiffInvalidWidth {
         #[primary_span]
diff --git a/compiler/rustc_builtin_macros/src/lib.rs b/compiler/rustc_builtin_macros/src/lib.rs
index a89b3642f7e..b16f3cff5cf 100644
--- a/compiler/rustc_builtin_macros/src/lib.rs
+++ b/compiler/rustc_builtin_macros/src/lib.rs
@@ -5,10 +5,10 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(not(bootstrap), feature(autodiff))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]
-#![feature(autodiff)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]
 #![feature(if_let_guard)]