1 files changed, 1 insertions, 1 deletions

diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index 541e6082f..b7388b98c 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -265,7 +265,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
 
     fn hidden_opaque_type(&self, _id: chalk_ir::OpaqueTyId<Interner>) -> chalk_ir::Ty<Interner> {
         // FIXME: actually provide the hidden type; it is relevant for auto traits
-        TyKind::Unknown.intern(&Interner).to_chalk(self.db)
+        TyKind::Error.intern(&Interner).to_chalk(self.db)
     }
 
     fn is_object_safe(&self, _trait_id: chalk_ir::TraitId<Interner>) -> bool {