2 files changed, 6 insertions, 4 deletions
diff --git a/compiler/rustc_mir/src/borrow_check/type_check/mod.rs b/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
index fddd1401868..3248554e204 100644
--- a/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
+++ b/compiler/rustc_mir/src/borrow_check/type_check/mod.rs
@@ -2028,7 +2028,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                                             traits::ObligationCauseCode::RepeatVec(is_const_fn),
                                         ),
                                         self.param_env,
-                                        ty::Binder::bind(ty::TraitRef::new(
+                                        ty::Binder::dummy(ty::TraitRef::new(
                                             self.tcx().require_lang_item(
                                                 LangItem::Copy,
                                                 Some(self.last_span),
diff --git a/compiler/rustc_mir/src/monomorphize/mod.rs b/compiler/rustc_mir/src/monomorphize/mod.rs
index d2586f0f84d..fd3f3b3a080 100644
--- a/compiler/rustc_mir/src/monomorphize/mod.rs
+++ b/compiler/rustc_mir/src/monomorphize/mod.rs
@@ -1,6 +1,6 @@
 use rustc_middle::traits;
 use rustc_middle::ty::adjustment::CustomCoerceUnsized;
-use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
 
 use rustc_hir::lang_items::LangItem;
 
@@ -8,14 +8,16 @@ pub mod collector;
 pub mod partitioning;
 pub mod polymorphize;
 
-pub fn custom_coerce_unsize_info<'tcx>(
+fn custom_coerce_unsize_info<'tcx>(
     tcx: TyCtxt<'tcx>,
     source_ty: Ty<'tcx>,
     target_ty: Ty<'tcx>,
 ) -> CustomCoerceUnsized {
     let def_id = tcx.require_lang_item(LangItem::CoerceUnsized, None);
 
-    let trait_ref = ty::Binder::bind(ty::TraitRef {
+    debug_assert!(!source_ty.has_escaping_bound_vars());
+    debug_assert!(!target_ty.has_escaping_bound_vars());
+    let trait_ref = ty::Binder::dummy(ty::TraitRef {
         def_id,
         substs: tcx.mk_substs_trait(source_ty, &[target_ty.into()]),
     });