2 files changed, 16 insertions, 7 deletions

diff --git a/crates/hir/src/display.rs b/crates/hir/src/display.rs
index 9f6d7be48..c96ebb50a 100644
--- a/crates/hir/src/display.rs
+++ b/crates/hir/src/display.rs
@@ -236,7 +236,11 @@ impl HirDisplay for TypeParam {
         write!(f, "{}", self.name(f.db))?;
         let bounds = f.db.generic_predicates_for_param(self.id);
         let substs = Substitution::type_params(f.db, self.id.parent);
-        let predicates = bounds.iter().cloned().map(|b| b.subst(&substs)).collect::<Vec<_>>();
+        let predicates = bounds
+            .iter()
+            .cloned()
+            .map(|b| hir_ty::Binders::new(0, b.subst(&substs)))
+            .collect::<Vec<_>>();
         if !(predicates.is_empty() || f.omit_verbose_types()) {
             write_bounds_like_dyn_trait_with_prefix(":", &predicates, f)?;
         }
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index e3ac37e4c..1844942a6 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -57,8 +57,8 @@ use hir_ty::{
     to_assoc_type_id,
     traits::{FnTrait, Solution, SolutionVariables},
     AliasEq, AliasTy, BoundVar, CallableDefId, CallableSig, Canonical, Cast, DebruijnIndex,
-    InEnvironment, Interner, ProjectionTy, Scalar, Substitution, Ty, TyDefId, TyKind,
-    TyVariableKind, WhereClause,
+    InEnvironment, Interner, ProjectionTy, QuantifiedWhereClause, Scalar, Substitution, Ty,
+    TyDefId, TyKind, TyVariableKind, WhereClause,
 };
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
@@ -2022,7 +2022,7 @@ impl Type {
     pub fn as_impl_traits(&self, db: &dyn HirDatabase) -> Option<Vec<Trait>> {
         self.ty.value.impl_trait_bounds(db).map(|it| {
             it.into_iter()
-                .filter_map(|pred| match pred {
+                .filter_map(|pred| match pred.skip_binders() {
                     hir_ty::WhereClause::Implemented(trait_ref) => {
                         Some(Trait::from(trait_ref.hir_trait_id()))
                     }
@@ -2061,11 +2061,11 @@ impl Type {
         fn walk_bounds(
             db: &dyn HirDatabase,
             type_: &Type,
-            bounds: &[WhereClause],
+            bounds: &[QuantifiedWhereClause],
             cb: &mut impl FnMut(Type),
         ) {
             for pred in bounds {
-                match pred {
+                match pred.skip_binders() {
                     WhereClause::Implemented(trait_ref) => {
                         cb(type_.clone());
                         // skip the self type. it's likely the type we just got the bounds from
@@ -2107,7 +2107,12 @@ impl Type {
                     }
                 }
                 TyKind::Dyn(bounds) => {
-                    walk_bounds(db, &type_.derived(ty.clone()), bounds.as_ref(), cb);
+                    walk_bounds(
+                        db,
+                        &type_.derived(ty.clone()),
+                        bounds.bounds.skip_binders().interned(),
+                        cb,
+                    );
                 }
 
                 TyKind::Ref(_, ty) | TyKind::Raw(_, ty) | TyKind::Array(ty) | TyKind::Slice(ty) => {