diff --git a/compiler/rustc_borrowck/src/diagnostics/region_name.rs b/compiler/rustc_borrowck/src/diagnostics/region_name.rs
index be6eb2d1d12..337af89b21f 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_name.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_name.rs
@@ -516,7 +516,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
                         // be the same as those of the ADT.
                         // FIXME: We should be able to do something similar to
                         // match_adt_and_segment in this case.
-                        Res::Def(DefKind::TyAlias, _) => (),
+                        Res::Def(DefKind::TyAlias { .. }, _) => (),
                         _ => {
                             if let Some(last_segment) = path.segments.last() {
                                 if let Some(highlight) = self.match_adt_and_segment(
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index 3a4eb90f7f9..64271309664 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -61,7 +61,9 @@ pub enum DefKind {
     Variant,
     Trait,
     /// Type alias: `type Foo = Bar;`
-    TyAlias,
+    TyAlias {
+        lazy: bool,
+    },
     /// Type from an `extern` block.
     ForeignTy,
     /// Trait alias: `trait IntIterator = Iterator<Item = i32>;`
@@ -141,7 +143,7 @@ impl DefKind {
             DefKind::Ctor(CtorOf::Struct, CtorKind::Fn) => "tuple struct",
             DefKind::Ctor(CtorOf::Struct, CtorKind::Const) => "unit struct",
             DefKind::OpaqueTy => "opaque type",
-            DefKind::TyAlias => "type alias",
+            DefKind::TyAlias { .. } => "type alias",
             DefKind::TraitAlias => "trait alias",
             DefKind::AssocTy => "associated type",
             DefKind::Union => "union",
@@ -197,7 +199,7 @@ impl DefKind {
             | DefKind::Variant
             | DefKind::Trait
             | DefKind::OpaqueTy
-            | DefKind::TyAlias
+            | DefKind::TyAlias { .. }
             | DefKind::ForeignTy
             | DefKind::TraitAlias
             | DefKind::AssocTy
@@ -248,7 +250,7 @@ impl DefKind {
             | DefKind::Enum
             | DefKind::Variant
             | DefKind::Trait
-            | DefKind::TyAlias
+            | DefKind::TyAlias { .. }
             | DefKind::ForeignTy
             | DefKind::TraitAlias
             | DefKind::AssocTy
diff --git a/compiler/rustc_hir/src/target.rs b/compiler/rustc_hir/src/target.rs
index 0d65ddb5642..644c4d8265d 100644
--- a/compiler/rustc_hir/src/target.rs
+++ b/compiler/rustc_hir/src/target.rs
@@ -101,7 +101,7 @@ impl Target {
             DefKind::Mod => Target::Mod,
             DefKind::ForeignMod => Target::ForeignMod,
             DefKind::GlobalAsm => Target::GlobalAsm,
-            DefKind::TyAlias => Target::TyAlias,
+            DefKind::TyAlias { .. } => Target::TyAlias,
             DefKind::OpaqueTy => Target::OpaqueTy,
             DefKind::Enum => Target::Enum,
             DefKind::Struct => Target::Struct,
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index b40e3123522..319573c85b4 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -907,19 +907,21 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         did: DefId,
         item_segment: &hir::PathSegment<'_>,
     ) -> Ty<'tcx> {
+        let tcx = self.tcx();
         let args = self.ast_path_args_for_ty(span, did, item_segment);
-        let ty = self.tcx().at(span).type_of(did);
+        let ty = tcx.at(span).type_of(did);
 
-        if matches!(self.tcx().def_kind(did), DefKind::TyAlias)
-            && (ty.skip_binder().has_opaque_types() || self.tcx().features().lazy_type_alias)
+        if let DefKind::TyAlias { lazy } = tcx.def_kind(did)
+            && (lazy || ty.skip_binder().has_opaque_types())
         {
             // Type aliases referring to types that contain opaque types (but aren't just directly
-            // referencing a single opaque type) get encoded as a type alias that normalization will
+            // referencing a single opaque type) as well as those defined in crates that have the
+            // feature `lazy_type_alias` enabled get encoded as a type alias that normalization will
             // then actually instantiate the where bounds of.
-            let alias_ty = self.tcx().mk_alias_ty(did, args);
-            Ty::new_alias(self.tcx(), ty::Weak, alias_ty)
+            let alias_ty = tcx.mk_alias_ty(did, args);
+            Ty::new_alias(tcx, ty::Weak, alias_ty)
         } else {
-            ty.instantiate(self.tcx(), args)
+            ty.instantiate(tcx, args)
         }
     }
 
@@ -2158,7 +2160,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             }
             Res::Def(
                 DefKind::Enum
-                | DefKind::TyAlias
+                | DefKind::TyAlias { .. }
                 | DefKind::Struct
                 | DefKind::Union
                 | DefKind::ForeignTy,
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index 73627a818e5..49307d96cc2 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -728,7 +728,7 @@ fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) {
                 check_opaque(tcx, id);
             }
         }
-        DefKind::TyAlias => {
+        DefKind::TyAlias { .. } => {
             let pty_ty = tcx.type_of(id.owner_id).instantiate_identity();
             let generics = tcx.generics_of(id.owner_id);
             check_type_params_are_used(tcx, &generics, pty_ty);
diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
index 3cc6f574aec..6dd0c840de6 100644
--- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
+++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs
@@ -1480,7 +1480,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
                 DefKind::Struct
                 | DefKind::Union
                 | DefKind::Enum
-                | DefKind::TyAlias
+                | DefKind::TyAlias { .. }
                 | DefKind::Trait,
                 def_id,
             ) if depth == 0 => Some(def_id),
@@ -1990,7 +1990,7 @@ fn is_late_bound_map(
 
                 hir::TyKind::Path(hir::QPath::Resolved(
                     None,
-                    hir::Path { res: Res::Def(DefKind::TyAlias, alias_def), segments, span },
+                    hir::Path { res: Res::Def(DefKind::TyAlias { .. }, alias_def), segments, span },
                 )) => {
                     // See comments on `ConstrainedCollectorPostAstConv` for why this arm does not just consider
                     // args to be unconstrained.
diff --git a/compiler/rustc_hir_analysis/src/variance/constraints.rs b/compiler/rustc_hir_analysis/src/variance/constraints.rs
index 4a3d522e488..8a40509d7cc 100644
--- a/compiler/rustc_hir_analysis/src/variance/constraints.rs
+++ b/compiler/rustc_hir_analysis/src/variance/constraints.rs
@@ -78,9 +78,8 @@ pub fn add_constraints_from_crate<'a, 'tcx>(
                 }
             }
             DefKind::Fn | DefKind::AssocFn => constraint_cx.build_constraints_for_item(def_id),
-            DefKind::TyAlias
-                if tcx.features().lazy_type_alias
-                    || tcx.type_of(def_id).instantiate_identity().has_opaque_types() =>
+            DefKind::TyAlias { lazy }
+                if lazy || tcx.type_of(def_id).instantiate_identity().has_opaque_types() =>
             {
                 constraint_cx.build_constraints_for_item(def_id)
             }
@@ -111,8 +110,8 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
 
         // The type as returned by `type_of` is the underlying type and generally not a weak projection.
         // Therefore we need to check the `DefKind` first.
-        if let DefKind::TyAlias = tcx.def_kind(def_id)
-            && (tcx.features().lazy_type_alias || ty.has_opaque_types())
+        if let DefKind::TyAlias { lazy } = tcx.def_kind(def_id)
+            && (lazy || ty.has_opaque_types())
         {
             self.add_constraints_from_ty(current_item, ty, self.covariant);
             return;
diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index 2ef294c6793..d91d9fcbc8e 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -56,9 +56,8 @@ fn variances_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Variance] {
             let crate_map = tcx.crate_variances(());
             return crate_map.variances.get(&item_def_id.to_def_id()).copied().unwrap_or(&[]);
         }
-        DefKind::TyAlias
-            if tcx.features().lazy_type_alias
-                || tcx.type_of(item_def_id).instantiate_identity().has_opaque_types() =>
+        DefKind::TyAlias { lazy }
+            if lazy || tcx.type_of(item_def_id).instantiate_identity().has_opaque_types() =>
         {
             // These are inferred.
             let crate_map = tcx.crate_variances(());
diff --git a/compiler/rustc_hir_analysis/src/variance/terms.rs b/compiler/rustc_hir_analysis/src/variance/terms.rs
index 1ef3d383bd8..1a8ec5f0853 100644
--- a/compiler/rustc_hir_analysis/src/variance/terms.rs
+++ b/compiler/rustc_hir_analysis/src/variance/terms.rs
@@ -97,9 +97,8 @@ pub fn determine_parameters_to_be_inferred<'a, 'tcx>(
                 }
             }
             DefKind::Fn | DefKind::AssocFn => terms_cx.add_inferreds_for_item(def_id),
-            DefKind::TyAlias
-                if tcx.features().lazy_type_alias
-                    || tcx.type_of(def_id).instantiate_identity().has_opaque_types() =>
+            DefKind::TyAlias { lazy }
+                if lazy || tcx.type_of(def_id).instantiate_identity().has_opaque_types() =>
             {
                 terms_cx.add_inferreds_for_item(def_id)
             }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index c63dab63145..40f9a954034 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -1359,7 +1359,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
                 _ => bug!("unexpected type: {:?}", ty.normalized),
             },
-            Res::Def(DefKind::Struct | DefKind::Union | DefKind::TyAlias | DefKind::AssocTy, _)
+            Res::Def(
+                DefKind::Struct | DefKind::Union | DefKind::TyAlias { .. } | DefKind::AssocTy,
+                _,
+            )
             | Res::SelfTyParam { .. }
             | Res::SelfTyAlias { .. } => match ty.normalized.ty_adt_def() {
                 Some(adt) if !adt.is_enum() => {
diff --git a/compiler/rustc_hir_typeck/src/mem_categorization.rs b/compiler/rustc_hir_typeck/src/mem_categorization.rs
index 4ea53c7eaae..7fb1dc2347e 100644
--- a/compiler/rustc_hir_typeck/src/mem_categorization.rs
+++ b/compiler/rustc_hir_typeck/src/mem_categorization.rs
@@ -557,7 +557,10 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> {
                 Ok(adt_def.variant_index_with_ctor_id(variant_ctor_id))
             }
             Res::Def(DefKind::Ctor(CtorOf::Struct, ..), _)
-            | Res::Def(DefKind::Struct | DefKind::Union | DefKind::TyAlias | DefKind::AssocTy, _)
+            | Res::Def(
+                DefKind::Struct | DefKind::Union | DefKind::TyAlias { .. } | DefKind::AssocTy,
+                _,
+            )
             | Res::SelfCtor(..)
             | Res::SelfTyParam { .. }
             | Res::SelfTyAlias { .. } => {
diff --git a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs
index 9dfa45858a7..f2a3c47bdfe 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs
@@ -951,7 +951,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> {
             //
             // See the `need_type_info/issue-103053.rs` test for
             // a example.
-            if !matches!(path.res, Res::Def(DefKind::TyAlias, _)) => {
+            if !matches!(path.res, Res::Def(DefKind::TyAlias { .. }, _)) => {
                 if let Some(ty) = self.opt_node_type(expr.hir_id)
                     && let ty::Adt(_, args) = ty.kind()
                 {
@@ -1080,7 +1080,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> {
                         ) => {
                             if tcx.res_generics_def_id(path.res) != Some(def.did()) {
                                 match path.res {
-                                    Res::Def(DefKind::TyAlias, _) => {
+                                    Res::Def(DefKind::TyAlias { .. }, _) => {
                                         // FIXME: Ideally we should support this. For that
                                         // we have to map back from the self type to the
                                         // type alias though. That's difficult.
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index f12094a271f..b34fead821f 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -819,7 +819,7 @@ fn should_encode_span(def_kind: DefKind) -> bool {
         | DefKind::Enum
         | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::TraitAlias
         | DefKind::AssocTy
@@ -854,7 +854,7 @@ fn should_encode_attrs(def_kind: DefKind) -> bool {
         | DefKind::Enum
         | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::TraitAlias
         | DefKind::AssocTy
@@ -895,7 +895,7 @@ fn should_encode_expn_that_defined(def_kind: DefKind) -> bool {
         | DefKind::Variant
         | DefKind::Trait
         | DefKind::Impl { .. } => true,
-        DefKind::TyAlias
+        DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::TraitAlias
         | DefKind::AssocTy
@@ -930,7 +930,7 @@ fn should_encode_visibility(def_kind: DefKind) -> bool {
         | DefKind::Enum
         | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::TraitAlias
         | DefKind::AssocTy
@@ -974,7 +974,7 @@ fn should_encode_stability(def_kind: DefKind) -> bool {
         | DefKind::Const
         | DefKind::Fn
         | DefKind::ForeignMod
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::OpaqueTy
         | DefKind::Enum
         | DefKind::Union
@@ -1067,9 +1067,8 @@ fn should_encode_variances<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, def_kind: Def
         | DefKind::Closure
         | DefKind::Generator
         | DefKind::ExternCrate => false,
-        DefKind::TyAlias => {
-            tcx.features().lazy_type_alias
-                || tcx.type_of(def_id).instantiate_identity().has_opaque_types()
+        DefKind::TyAlias { lazy } => {
+            lazy || tcx.type_of(def_id).instantiate_identity().has_opaque_types()
         }
     }
 }
@@ -1081,7 +1080,7 @@ fn should_encode_generics(def_kind: DefKind) -> bool {
         | DefKind::Enum
         | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::TraitAlias
         | DefKind::AssocTy
@@ -1121,7 +1120,7 @@ fn should_encode_type(tcx: TyCtxt<'_>, def_id: LocalDefId, def_kind: DefKind) ->
         | DefKind::Fn
         | DefKind::Const
         | DefKind::Static(..)
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::Impl { .. }
         | DefKind::AssocFn
@@ -1181,7 +1180,7 @@ fn should_encode_fn_sig(def_kind: DefKind) -> bool {
         | DefKind::Const
         | DefKind::Static(..)
         | DefKind::Ctor(..)
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::OpaqueTy
         | DefKind::ForeignTy
         | DefKind::Impl { .. }
@@ -1222,7 +1221,7 @@ fn should_encode_constness(def_kind: DefKind) -> bool {
         | DefKind::AssocConst
         | DefKind::AnonConst
         | DefKind::Static(..)
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::OpaqueTy
         | DefKind::Impl { of_trait: false }
         | DefKind::ForeignTy
@@ -1255,7 +1254,7 @@ fn should_encode_const(def_kind: DefKind) -> bool {
         | DefKind::Field
         | DefKind::Fn
         | DefKind::Static(..)
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::OpaqueTy
         | DefKind::ForeignTy
         | DefKind::Impl { .. }
diff --git a/compiler/rustc_metadata/src/rmeta/table.rs b/compiler/rustc_metadata/src/rmeta/table.rs
index 4287799a8e6..ea66c770b77 100644
--- a/compiler/rustc_metadata/src/rmeta/table.rs
+++ b/compiler/rustc_metadata/src/rmeta/table.rs
@@ -126,7 +126,8 @@ fixed_size_enum! {
         ( Enum                                     )
         ( Variant                                  )
         ( Trait                                    )
-        ( TyAlias                                  )
+        ( TyAlias { lazy: false }                  )
+        ( TyAlias { lazy: true }                   )
         ( ForeignTy                                )
         ( TraitAlias                               )
         ( AssocTy                                  )
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index 2aebb8f541f..fbc32263874 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -196,7 +196,9 @@ impl<'hir> Map<'hir> {
                 ItemKind::Macro(_, macro_kind) => DefKind::Macro(macro_kind),
                 ItemKind::Mod(..) => DefKind::Mod,
                 ItemKind::OpaqueTy(..) => DefKind::OpaqueTy,
-                ItemKind::TyAlias(..) => DefKind::TyAlias,
+                ItemKind::TyAlias(..) => {
+                    DefKind::TyAlias { lazy: self.tcx.features().lazy_type_alias }
+                }
                 ItemKind::Enum(..) => DefKind::Enum,
                 ItemKind::Struct(..) => DefKind::Struct,
                 ItemKind::Union(..) => DefKind::Union,
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 533c3b66cab..52a18c99edb 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -231,7 +231,7 @@ rustc_queries! {
             action = {
                 use rustc_hir::def::DefKind;
                 match tcx.def_kind(key) {
-                    DefKind::TyAlias => "expanding type alias",
+                    DefKind::TyAlias { .. } => "expanding type alias",
                     DefKind::TraitAlias => "expanding trait alias",
                     _ => "computing type of",
                 }
diff --git a/compiler/rustc_middle/src/ty/adt.rs b/compiler/rustc_middle/src/ty/adt.rs
index 6ba13a76563..b4c6e0d970a 100644
--- a/compiler/rustc_middle/src/ty/adt.rs
+++ b/compiler/rustc_middle/src/ty/adt.rs
@@ -448,7 +448,7 @@ impl<'tcx> AdtDef<'tcx> {
             Res::Def(DefKind::Ctor(..), cid) => self.variant_with_ctor_id(cid),
             Res::Def(DefKind::Struct, _)
             | Res::Def(DefKind::Union, _)
-            | Res::Def(DefKind::TyAlias, _)
+            | Res::Def(DefKind::TyAlias { .. }, _)
             | Res::Def(DefKind::AssocTy, _)
             | Res::SelfTyParam { .. }
             | Res::SelfTyAlias { .. }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 5eef3e45f32..0b2d95506bf 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1062,7 +1062,7 @@ impl<'tcx> TyCtxt<'tcx> {
         if let Some(hir::FnDecl { output: hir::FnRetTy::Return(hir_output), .. }) = self.hir().fn_decl_by_hir_id(hir_id)
             && let hir::TyKind::Path(hir::QPath::Resolved(
                 None,
-                hir::Path { res: hir::def::Res::Def(DefKind::TyAlias, def_id), .. }, )) = hir_output.kind
+                hir::Path { res: hir::def::Res::Def(DefKind::TyAlias { .. }, def_id), .. }, )) = hir_output.kind
             && let Some(local_id) = def_id.as_local()
             && let Some(alias_ty) = self.hir().get_by_def_id(local_id).alias_ty() // it is type alias
             && let Some(alias_generics) = self.hir().get_by_def_id(local_id).generics()
diff --git a/compiler/rustc_middle/src/ty/diagnostics.rs b/compiler/rustc_middle/src/ty/diagnostics.rs
index 8570f83dcc6..e71482326da 100644
--- a/compiler/rustc_middle/src/ty/diagnostics.rs
+++ b/compiler/rustc_middle/src/ty/diagnostics.rs
@@ -492,7 +492,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for IsSuggestableVisitor<'tcx> {
             Alias(Opaque, AliasTy { def_id, .. }) => {
                 let parent = self.tcx.parent(def_id);
                 let parent_ty = self.tcx.type_of(parent).instantiate_identity();
-                if let DefKind::TyAlias | DefKind::AssocTy = self.tcx.def_kind(parent)
+                if let DefKind::TyAlias { .. } | DefKind::AssocTy = self.tcx.def_kind(parent)
                     && let Alias(Opaque, AliasTy { def_id: parent_opaque_def_id, .. }) = *parent_ty.kind()
                     && parent_opaque_def_id == def_id
                 {
@@ -576,7 +576,7 @@ impl<'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for MakeSuggestableFolder<'tcx> {
             Alias(Opaque, AliasTy { def_id, .. }) => {
                 let parent = self.tcx.parent(def_id);
                 let parent_ty = self.tcx.type_of(parent).instantiate_identity();
-                if let hir::def::DefKind::TyAlias | hir::def::DefKind::AssocTy = self.tcx.def_kind(parent)
+                if let hir::def::DefKind::TyAlias { .. } | hir::def::DefKind::AssocTy = self.tcx.def_kind(parent)
                     && let Alias(Opaque, AliasTy { def_id: parent_opaque_def_id, .. }) = *parent_ty.kind()
                     && parent_opaque_def_id == def_id
                 {
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index d3fd49150ba..27ade16739d 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -364,7 +364,7 @@ pub trait PrettyPrinter<'tcx>:
                 self.write_str(get_local_name(&self, symbol, parent, parent_key).as_str())?;
                 self.write_str("::")?;
             } else if let DefKind::Struct | DefKind::Union | DefKind::Enum | DefKind::Trait
-                | DefKind::TyAlias | DefKind::Fn | DefKind::Const | DefKind::Static(_) = kind
+                | DefKind::TyAlias { .. } | DefKind::Fn | DefKind::Const | DefKind::Static(_) = kind
             {
             } else {
                 // If not covered above, like for example items out of `impl` blocks, fallback.
@@ -766,7 +766,7 @@ pub trait PrettyPrinter<'tcx>:
 
                 let parent = self.tcx().parent(def_id);
                 match self.tcx().def_kind(parent) {
-                    DefKind::TyAlias | DefKind::AssocTy => {
+                    DefKind::TyAlias { .. } | DefKind::AssocTy => {
                         // NOTE: I know we should check for NO_QUERIES here, but it's alright.
                         // `type_of` on a type alias or assoc type should never cause a cycle.
                         if let ty::Alias(ty::Opaque, ty::AliasTy { def_id: d, .. }) =
@@ -2983,7 +2983,7 @@ fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, N
 
             match child.res {
                 def::Res::Def(DefKind::AssocTy, _) => {}
-                def::Res::Def(DefKind::TyAlias, _) => {}
+                def::Res::Def(DefKind::TyAlias { .. }, _) => {}
                 def::Res::Def(defkind, def_id) => {
                     if let Some(ns) = defkind.ns() {
                         collect_fn(&child.ident, ns, def_id);
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index a695febf087..e6baa624205 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -1223,7 +1223,7 @@ impl<'tcx> AliasTy<'tcx> {
             DefKind::AssocTy if let DefKind::Impl { of_trait: false } = tcx.def_kind(tcx.parent(self.def_id)) => ty::Inherent,
             DefKind::AssocTy => ty::Projection,
             DefKind::OpaqueTy => ty::Opaque,
-            DefKind::TyAlias => ty::Weak,
+            DefKind::TyAlias { .. } => ty::Weak,
             kind => bug!("unexpected DefKind in AliasTy: {kind:?}"),
         }
     }
@@ -1945,7 +1945,7 @@ impl<'tcx> Ty<'tcx> {
             (kind, tcx.def_kind(alias_ty.def_id)),
             (ty::Opaque, DefKind::OpaqueTy)
                 | (ty::Projection | ty::Inherent, DefKind::AssocTy)
-                | (ty::Weak, DefKind::TyAlias)
+                | (ty::Weak, DefKind::TyAlias { .. })
         );
         Ty::new(tcx, Alias(kind, alias_ty))
     }
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index 90ecc8aa857..564f982f842 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -156,7 +156,7 @@ impl<'tcx> TyCtxt<'tcx> {
                 | DefKind::Enum
                 | DefKind::Trait
                 | DefKind::OpaqueTy
-                | DefKind::TyAlias
+                | DefKind::TyAlias { .. }
                 | DefKind::ForeignTy
                 | DefKind::TraitAlias
                 | DefKind::AssocTy
diff --git a/compiler/rustc_middle/src/values.rs b/compiler/rustc_middle/src/values.rs
index b0961d91787..384a368434a 100644
--- a/compiler/rustc_middle/src/values.rs
+++ b/compiler/rustc_middle/src/values.rs
@@ -209,7 +209,7 @@ fn find_item_ty_spans(
     match ty.kind {
         hir::TyKind::Path(hir::QPath::Resolved(_, path)) => {
             if let Res::Def(kind, def_id) = path.res
-                && kind != DefKind::TyAlias {
+                && !matches!(kind, DefKind::TyAlias { .. }) {
                 let check_params = def_id.as_local().map_or(true, |def_id| {
                     if def_id == needle {
                         spans.push(ty.span);
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
index 3c3cbbf3614..c08fe54c39c 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
@@ -439,7 +439,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
                 DefKind::Struct
                 | DefKind::Ctor(CtorOf::Struct, ..)
                 | DefKind::Union
-                | DefKind::TyAlias
+                | DefKind::TyAlias { .. }
                 | DefKind::AssocTy,
                 _,
             )
diff --git a/compiler/rustc_monomorphize/src/polymorphize.rs b/compiler/rustc_monomorphize/src/polymorphize.rs
index d31bf2072b1..a8b7a0dbb68 100644
--- a/compiler/rustc_monomorphize/src/polymorphize.rs
+++ b/compiler/rustc_monomorphize/src/polymorphize.rs
@@ -143,7 +143,7 @@ fn mark_used_by_default_parameters<'tcx>(
         | DefKind::Enum
         | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::TraitAlias
         | DefKind::AssocTy
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index fbe6fc3bee4..07b437f463f 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -87,7 +87,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
 
     fn handle_res(&mut self, res: Res) {
         match res {
-            Res::Def(DefKind::Const | DefKind::AssocConst | DefKind::TyAlias, def_id) => {
+            Res::Def(DefKind::Const | DefKind::AssocConst | DefKind::TyAlias { .. }, def_id) => {
                 self.check_def_id(def_id);
             }
             _ if self.in_pat => {}
@@ -861,7 +861,7 @@ impl<'tcx> DeadVisitor<'tcx> {
             | DefKind::Fn
             | DefKind::Static(_)
             | DefKind::Const
-            | DefKind::TyAlias
+            | DefKind::TyAlias { .. }
             | DefKind::Enum
             | DefKind::Union
             | DefKind::ForeignTy => self.warn_dead_code(def_id, "used"),
diff --git a/compiler/rustc_passes/src/layout_test.rs b/compiler/rustc_passes/src/layout_test.rs
index 794dbda3688..0463ee2914b 100644
--- a/compiler/rustc_passes/src/layout_test.rs
+++ b/compiler/rustc_passes/src/layout_test.rs
@@ -16,7 +16,7 @@ pub fn test_layout(tcx: TyCtxt<'_>) {
         for id in tcx.hir().items() {
             if matches!(
                 tcx.def_kind(id.owner_id),
-                DefKind::TyAlias | DefKind::Enum | DefKind::Struct | DefKind::Union
+                DefKind::TyAlias { .. } | DefKind::Enum | DefKind::Struct | DefKind::Union
             ) {
                 for attr in tcx.get_attrs(id.owner_id, sym::rustc_layout) {
                     dump_layout_of(tcx, id.owner_id.def_id, attr);
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index af9efb82beb..30a4235d371 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -583,7 +583,7 @@ impl<'tcx> EmbargoVisitor<'tcx> {
         self.update(def_id, macro_ev, Level::Reachable);
         match def_kind {
             // No type privacy, so can be directly marked as reachable.
-            DefKind::Const | DefKind::Static(_) | DefKind::TraitAlias | DefKind::TyAlias => {
+            DefKind::Const | DefKind::Static(_) | DefKind::TraitAlias | DefKind::TyAlias { .. } => {
                 if vis.is_accessible_from(module, self.tcx) {
                     self.update(def_id, macro_ev, Level::Reachable);
                 }
@@ -1992,8 +1992,8 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'tcx, '_> {
         let def_kind = tcx.def_kind(def_id);
 
         match def_kind {
-            DefKind::Const | DefKind::Static(_) | DefKind::Fn | DefKind::TyAlias => {
-                if let DefKind::TyAlias = def_kind {
+            DefKind::Const | DefKind::Static(_) | DefKind::Fn | DefKind::TyAlias { .. } => {
+                if let DefKind::TyAlias { .. } = def_kind {
                     self.check_unnameable(def_id, effective_vis);
                 }
                 self.check(def_id, item_visibility, effective_vis).generics().predicates().ty();
diff --git a/compiler/rustc_query_system/src/query/job.rs b/compiler/rustc_query_system/src/query/job.rs
index bfc51da170d..1b124892441 100644
--- a/compiler/rustc_query_system/src/query/job.rs
+++ b/compiler/rustc_query_system/src/query/job.rs
@@ -592,7 +592,10 @@ pub(crate) fn report_cycle<'a, D: DepKind>(
         });
     }
 
-    let alias = if stack.iter().all(|entry| entry.query.def_kind == Some(DefKind::TyAlias)) {
+    let alias = if stack
+        .iter()
+        .all(|entry| matches!(entry.query.def_kind, Some(DefKind::TyAlias { .. })))
+    {
         Some(crate::error::Alias::Ty)
     } else if stack.iter().all(|entry| entry.query.def_kind == Some(DefKind::TraitAlias)) {
         Some(crate::error::Alias::Trait)
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index 80d6a47ff53..a655667d01d 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -700,7 +700,10 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
 
             // These items live in the type namespace.
             ItemKind::TyAlias(..) => {
-                let res = Res::Def(DefKind::TyAlias, def_id);
+                let res = Res::Def(
+                    DefKind::TyAlias { lazy: self.r.tcx.features().lazy_type_alias },
+                    def_id,
+                );
                 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
             }
 
@@ -948,7 +951,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 DefKind::Struct
                 | DefKind::Union
                 | DefKind::Variant
-                | DefKind::TyAlias
+                | DefKind::TyAlias { .. }
                 | DefKind::ForeignTy
                 | DefKind::OpaqueTy
                 | DefKind::TraitAlias
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 65fa077dcd9..6007295b930 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -470,7 +470,7 @@ impl<'a> PathSource<'a> {
                         | DefKind::Enum
                         | DefKind::Trait
                         | DefKind::TraitAlias
-                        | DefKind::TyAlias
+                        | DefKind::TyAlias { .. }
                         | DefKind::AssocTy
                         | DefKind::TyParam
                         | DefKind::OpaqueTy
@@ -509,7 +509,7 @@ impl<'a> PathSource<'a> {
                     DefKind::Struct
                         | DefKind::Union
                         | DefKind::Variant
-                        | DefKind::TyAlias
+                        | DefKind::TyAlias { .. }
                         | DefKind::AssocTy,
                     _,
                 ) | Res::SelfTyParam { .. }
@@ -1740,7 +1740,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 Res::Def(DefKind::Struct, def_id)
                 | Res::Def(DefKind::Union, def_id)
                 | Res::Def(DefKind::Enum, def_id)
-                | Res::Def(DefKind::TyAlias, def_id)
+                | Res::Def(DefKind::TyAlias { .. }, def_id)
                 | Res::Def(DefKind::Trait, def_id)
                     if i + 1 == proj_start =>
                 {
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 9edcb5255b2..ba9bbbb1463 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -1419,7 +1419,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             (Res::Def(DefKind::Macro(MacroKind::Bang), _), _) => {
                 err.span_label(span, fallback_label.to_string());
             }
-            (Res::Def(DefKind::TyAlias, def_id), PathSource::Trait(_)) => {
+            (Res::Def(DefKind::TyAlias { .. }, def_id), PathSource::Trait(_)) => {
                 err.span_label(span, "type aliases cannot be used as traits");
                 if self.r.tcx.sess.is_nightly_build() {
                     let msg = "you might have meant to use `#![feature(trait_alias)]` instead of a \
@@ -1588,7 +1588,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 err.span_label(span, fallback_label.to_string());
                 err.note("can't use `Self` as a constructor, you must use the implemented struct");
             }
-            (Res::Def(DefKind::TyAlias | DefKind::AssocTy, _), _) if ns == ValueNS => {
+            (Res::Def(DefKind::TyAlias { .. } | DefKind::AssocTy, _), _) if ns == ValueNS => {
                 err.note("can't use a type alias as a constructor");
             }
             _ => return false,
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals.rs
index 75cf33d8194..e1980f4d7bb 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals.rs
@@ -58,7 +58,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             }
             DefKind::AnonConst => self.normalize_anon_const(goal),
             DefKind::OpaqueTy => self.normalize_opaque_type(goal),
-            DefKind::TyAlias => self.normalize_weak_type(goal),
+            DefKind::TyAlias { .. } => self.normalize_weak_type(goal),
             kind => bug!("unknown DefKind {} in projection goal: {goal:#?}", kind.descr(def_id)),
         }
     }
diff --git a/compiler/rustc_ty_utils/src/implied_bounds.rs b/compiler/rustc_ty_utils/src/implied_bounds.rs
index 7eb1042d2f8..aa49a5561d1 100644
--- a/compiler/rustc_ty_utils/src/implied_bounds.rs
+++ b/compiler/rustc_ty_utils/src/implied_bounds.rs
@@ -128,7 +128,7 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'
         },
         DefKind::AssocConst | DefKind::AssocTy => tcx.assumed_wf_types(tcx.local_parent(def_id)),
         DefKind::OpaqueTy => match tcx.def_kind(tcx.local_parent(def_id)) {
-            DefKind::TyAlias => ty::List::empty(),
+            DefKind::TyAlias { .. } => ty::List::empty(),
             DefKind::AssocTy => tcx.assumed_wf_types(tcx.local_parent(def_id)),
             // Nested opaque types only occur in associated types:
             // ` type Opaque<T> = impl Trait<&'static T, AssocTy = impl Nested>; `
@@ -145,7 +145,7 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'
         | DefKind::Enum
         | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
+        | DefKind::TyAlias { .. }
         | DefKind::ForeignTy
         | DefKind::TraitAlias
         | DefKind::TyParam
diff --git a/compiler/rustc_ty_utils/src/opaque_types.rs b/compiler/rustc_ty_utils/src/opaque_types.rs
index 06a30677d20..38768f0a05b 100644
--- a/compiler/rustc_ty_utils/src/opaque_types.rs
+++ b/compiler/rustc_ty_utils/src/opaque_types.rs
@@ -53,7 +53,9 @@ impl<'tcx> OpaqueTypeCollector<'tcx> {
 
     fn parent(&self) -> Option<LocalDefId> {
         match self.tcx.def_kind(self.item) {
-            DefKind::AnonConst | DefKind::InlineConst | DefKind::Fn | DefKind::TyAlias => None,
+            DefKind::AnonConst | DefKind::InlineConst | DefKind::Fn | DefKind::TyAlias { .. } => {
+                None
+            }
             DefKind::AssocFn | DefKind::AssocTy | DefKind::AssocConst => {
                 Some(self.tcx.local_parent(self.item))
             }
@@ -116,7 +118,7 @@ impl<'tcx> OpaqueTypeCollector<'tcx> {
             #[instrument(level = "trace", skip(self))]
             fn visit_nested_item(&mut self, id: rustc_hir::ItemId) {
                 let id = id.owner_id.def_id;
-                if let DefKind::TyAlias = self.collector.tcx.def_kind(id) {
+                if let DefKind::TyAlias { .. } = self.collector.tcx.def_kind(id) {
                     let items = self.collector.tcx.opaque_types_defined_by(id);
                     self.collector.opaques.extend(items);
                 }
@@ -295,7 +297,7 @@ fn opaque_types_defined_by<'tcx>(tcx: TyCtxt<'tcx>, item: LocalDefId) -> &'tcx [
             collector.collect_body_and_predicate_taits();
         }
         // We're also doing this for `AssocTy` for the wf checks in `check_opaque_meets_bounds`
-        DefKind::TyAlias | DefKind::AssocTy => {
+        DefKind::TyAlias { .. } | DefKind::AssocTy => {
             tcx.type_of(item).instantiate_identity().visit_with(&mut collector);
         }
         DefKind::OpaqueTy => {
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index c31d104f8cb..384010034e6 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -79,7 +79,7 @@ pub(crate) fn try_inline(
             build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::UnionItem(build_union(cx, did))
         }
-        Res::Def(DefKind::TyAlias, did) => {
+        Res::Def(DefKind::TyAlias { .. }, did) => {
             record_extern_fqn(cx, did, ItemType::Typedef);
             build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::TypedefItem(build_type_alias(cx, did))
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index a5efcc989f6..b6ba4c853d4 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1706,7 +1706,7 @@ fn maybe_expand_private_type_alias<'tcx>(
     cx: &mut DocContext<'tcx>,
     path: &hir::Path<'tcx>,
 ) -> Option<Type> {
-    let Res::Def(DefKind::TyAlias, def_id) = path.res else { return None };
+    let Res::Def(DefKind::TyAlias { .. }, def_id) = path.res else { return None };
     // Substitute private type aliases
     let def_id = def_id.as_local()?;
     let alias = if !cx.cache.effective_visibilities.is_exported(cx.tcx, def_id.to_def_id())
@@ -1970,7 +1970,7 @@ impl<'tcx> ContainerTy<'tcx> {
                 let (DefKind::Struct
                 | DefKind::Union
                 | DefKind::Enum
-                | DefKind::TyAlias
+                | DefKind::TyAlias { .. }
                 | DefKind::Trait
                 | DefKind::AssocTy
                 | DefKind::Variant) = tcx.def_kind(container)
@@ -2709,7 +2709,7 @@ fn clean_impl<'tcx>(
     let for_ = clean_ty(impl_.self_ty, cx);
     let type_alias =
         for_.def_id(&cx.cache).and_then(|alias_def_id: DefId| match tcx.def_kind(alias_def_id) {
-            DefKind::TyAlias => Some(clean_middle_ty(
+            DefKind::TyAlias { .. } => Some(clean_middle_ty(
                 ty::Binder::dummy(tcx.type_of(def_id).instantiate_identity()),
                 cx,
                 Some(def_id.to_def_id()),
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
index 944d0145de2..3c79ce57782 100644
--- a/src/librustdoc/clean/utils.rs
+++ b/src/librustdoc/clean/utils.rs
@@ -504,8 +504,22 @@ pub(crate) fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
 
     let (kind, did) = match res {
         Res::Def(
-            kind @ (AssocTy | AssocFn | AssocConst | Variant | Fn | TyAlias | Enum | Trait | Struct
-            | Union | Mod | ForeignTy | Const | Static(_) | Macro(..) | TraitAlias),
+            kind @ (AssocTy
+            | AssocFn
+            | AssocConst
+            | Variant
+            | Fn
+            | TyAlias { .. }
+            | Enum
+            | Trait
+            | Struct
+            | Union
+            | Mod
+            | ForeignTy
+            | Const
+            | Static(_)
+            | Macro(..)
+            | TraitAlias),
             did,
         ) => (kind.into(), did),
 
diff --git a/src/librustdoc/formats/item_type.rs b/src/librustdoc/formats/item_type.rs
index a3017201cb1..a788935581f 100644
--- a/src/librustdoc/formats/item_type.rs
+++ b/src/librustdoc/formats/item_type.rs
@@ -115,7 +115,7 @@ impl From<DefKind> for ItemType {
             DefKind::Struct => Self::Struct,
             DefKind::Union => Self::Union,
             DefKind::Trait => Self::Trait,
-            DefKind::TyAlias => Self::Typedef,
+            DefKind::TyAlias { .. } => Self::Typedef,
             DefKind::TraitAlias => Self::TraitAlias,
             DefKind::Macro(kind) => match kind {
                 MacroKind::Bang => ItemType::Macro,
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 4de30e4ed9d..1b8d999024c 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -592,7 +592,7 @@ impl<'a, 'tcx> LinkCollector<'a, 'tcx> {
                         .unwrap_or(Vec::new())
                 }
             }
-            Res::Def(DefKind::TyAlias, did) => {
+            Res::Def(DefKind::TyAlias { .. }, did) => {
                 // Resolve the link on the type the alias points to.
                 // FIXME: if the associated item is defined directly on the type alias,
                 // it will show up on its documentation page, we should link there instead.
@@ -1865,7 +1865,12 @@ fn resolution_failure(
                                 }
                                 return;
                             }
-                            Trait | TyAlias | ForeignTy | OpaqueTy | TraitAlias | TyParam
+                            Trait
+                            | TyAlias { .. }
+                            | ForeignTy
+                            | OpaqueTy
+                            | TraitAlias
+                            | TyParam
                             | Static(_) => "associated item",
                             Impl { .. } | GlobalAsm => unreachable!("not a path"),
                         }
diff --git a/src/tools/clippy/clippy_lints/src/init_numbered_fields.rs b/src/tools/clippy/clippy_lints/src/init_numbered_fields.rs
index f95d2c2edb1..b00fa104f98 100644
--- a/src/tools/clippy/clippy_lints/src/init_numbered_fields.rs
+++ b/src/tools/clippy/clippy_lints/src/init_numbered_fields.rs
@@ -50,7 +50,7 @@ impl<'tcx> LateLintPass<'tcx> for NumberedFields {
                 && fields
                     .iter()
                     .all(|f| f.ident.as_str().as_bytes().iter().all(u8::is_ascii_digit))
-                && !matches!(cx.qpath_res(path, e.hir_id), Res::Def(DefKind::TyAlias, ..))
+                && !matches!(cx.qpath_res(path, e.hir_id), Res::Def(DefKind::TyAlias { .. }, ..))
             {
                 let expr_spans = fields
                     .iter()
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index 4cd8a8c3325..171b7faf219 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -286,7 +286,7 @@ pub fn is_wild(pat: &Pat<'_>) -> bool {
 /// Checks if the given `QPath` belongs to a type alias.
 pub fn is_ty_alias(qpath: &QPath<'_>) -> bool {
     match *qpath {
-        QPath::Resolved(_, path) => matches!(path.res, Res::Def(DefKind::TyAlias | DefKind::AssocTy, ..)),
+        QPath::Resolved(_, path) => matches!(path.res, Res::Def(DefKind::TyAlias { .. } | DefKind::AssocTy, ..)),
         QPath::TypeRelative(ty, _) if let TyKind::Path(qpath) = ty.kind => { is_ty_alias(&qpath) },
         _ => false,
     }
diff --git a/src/tools/clippy/clippy_utils/src/ty/type_certainty/mod.rs b/src/tools/clippy/clippy_utils/src/ty/type_certainty/mod.rs
index 0669ea72eb3..06fd9529044 100644
--- a/src/tools/clippy/clippy_utils/src/ty/type_certainty/mod.rs
+++ b/src/tools/clippy/clippy_utils/src/ty/type_certainty/mod.rs
@@ -219,7 +219,7 @@ fn path_segment_certainty(
                 // See the comment preceding `qpath_certainty`. `def_id` could refer to a type or a value.
                 let certainty = lhs.join_clearing_def_ids(rhs);
                 if resolves_to_type {
-                    if cx.tcx.def_kind(def_id) == DefKind::TyAlias {
+                    if let DefKind::TyAlias { .. } = cx.tcx.def_kind(def_id) {
                         adt_def_id(cx.tcx.type_of(def_id).instantiate_identity())
                             .map_or(certainty, |def_id| certainty.with_def_id(def_id))
                     } else {
diff --git a/tests/ui/lazy-type-alias/auxiliary/eager.rs b/tests/ui/lazy-type-alias/auxiliary/eager.rs
new file mode 100644
index 00000000000..8793a1701ec
--- /dev/null
+++ b/tests/ui/lazy-type-alias/auxiliary/eager.rs
@@ -0,0 +1,6 @@
+// This crate does *not* have lazy type aliases enabled.
+
+#![allow(type_alias_bounds)]
+
+// The `Copy` bound is ignored both locally and externally for backward compatibility.
+pub type Alias<T: Copy> = Option<T>;
diff --git a/tests/ui/lazy-type-alias/auxiliary/lazy.rs b/tests/ui/lazy-type-alias/auxiliary/lazy.rs
new file mode 100644
index 00000000000..caa7999b4f7
--- /dev/null
+++ b/tests/ui/lazy-type-alias/auxiliary/lazy.rs
@@ -0,0 +1,4 @@
+#![feature(lazy_type_alias)]
+#![allow(incomplete_features)]
+
+pub type Alias<T: Copy> = Option<T>;
diff --git a/tests/ui/lazy-type-alias/extern-crate-has-eager-type-aliases.rs b/tests/ui/lazy-type-alias/extern-crate-has-eager-type-aliases.rs
new file mode 100644
index 00000000000..07389961c4c
--- /dev/null
+++ b/tests/ui/lazy-type-alias/extern-crate-has-eager-type-aliases.rs
@@ -0,0 +1,23 @@
+// This test serves as a regression test for issue #114468 and it also ensures that we consider
+// type aliases from external crates that don't have `lazy_type_alias` enabled to be eager.
+
+// aux-crate:eager=eager.rs
+// edition: 2021
+// check-pass
+
+#![feature(lazy_type_alias)]
+#![allow(incomplete_features)]
+
+// This used to crash when we were computing the variances of `Struct` since we would convert
+// `eager::Alias<T>` to a weak projection due to the presence of `#![feature(lazy_type_alias)]` in
+// this (!) crate and subsequently attempt to obtain the variances of the type alias associated with
+// the weak projection which would panic because we don't compute this information for eager type
+// aliases at all.
+struct Struct<T>(eager::Alias<T>);
+
+fn main() {
+    // We want to ignore (or rather “end up ignoring”) the bound `T: Copy` since `Alias` should be
+    // treated as an eager type alias not just inside the crate it is defined in but also in
+    // dependent crates (like this one).
+    let _: eager::Alias<String>;
+}
diff --git a/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.locally_eager.stderr b/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.locally_eager.stderr
new file mode 100644
index 00000000000..9e0e2bfa872
--- /dev/null
+++ b/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.locally_eager.stderr
@@ -0,0 +1,15 @@
+error[E0277]: the trait bound `String: Copy` is not satisfied
+  --> $DIR/extern-crate-has-lazy-type-aliases.rs:15:12
+   |
+LL |     let _: lazy::Alias<String>;
+   |            ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |
+note: required by a bound on the type alias `Alias`
+  --> $DIR/auxiliary/lazy.rs:4:19
+   |
+LL | pub type Alias<T: Copy> = Option<T>;
+   |                   ^^^^ required by this bound
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.locally_lazy.stderr b/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.locally_lazy.stderr
new file mode 100644
index 00000000000..9e0e2bfa872
--- /dev/null
+++ b/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.locally_lazy.stderr
@@ -0,0 +1,15 @@
+error[E0277]: the trait bound `String: Copy` is not satisfied
+  --> $DIR/extern-crate-has-lazy-type-aliases.rs:15:12
+   |
+LL |     let _: lazy::Alias<String>;
+   |            ^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |
+note: required by a bound on the type alias `Alias`
+  --> $DIR/auxiliary/lazy.rs:4:19
+   |
+LL | pub type Alias<T: Copy> = Option<T>;
+   |                   ^^^^ required by this bound
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.rs b/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.rs
new file mode 100644
index 00000000000..31a19161b6c
--- /dev/null
+++ b/tests/ui/lazy-type-alias/extern-crate-has-lazy-type-aliases.rs
@@ -0,0 +1,16 @@
+// revisions: locally_eager locally_lazy
+// aux-crate:lazy=lazy.rs
+// edition: 2021
+
+// Test that we treat lazy type aliases from external crates as lazy independently of whether the
+// local crate enables `lazy_type_alias` or not.
+
+#![cfg_attr(
+    locally_lazy,
+    feature(lazy_type_alias),
+    allow(incomplete_features)
+)]
+
+fn main() {
+    let _: lazy::Alias<String>; //~ ERROR the trait bound `String: Copy` is not satisfied
+}