diff --git a/compiler/rustc_attr_data_structures/src/attributes.rs b/compiler/rustc_attr_data_structures/src/attributes.rs
index 995ac514d8d6c..5f38be346edd3 100644
--- a/compiler/rustc_attr_data_structures/src/attributes.rs
+++ b/compiler/rustc_attr_data_structures/src/attributes.rs
@@ -417,6 +417,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_unsafe_specialization_marker]`.
     UnsafeSpecializationMarker(Span),
 
+    /// Represents `#[unstable_feature_bound]`.
+    UnstableFeatureBound(ThinVec<(Symbol, Span)>),
+
     /// Represents `#[used]`
     Used { used_by: UsedBy, span: Span },
     // tidy-alphabetical-end
diff --git a/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs b/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs
index 494b570c86c73..84c3bd1eb6147 100644
--- a/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs
+++ b/compiler/rustc_attr_data_structures/src/encode_cross_crate.rs
@@ -70,6 +70,7 @@ impl AttributeKind {
             TrackCaller(..) => Yes,
             TypeConst(..) => Yes,
             UnsafeSpecializationMarker(..) => No,
+            UnstableFeatureBound(..) => No,
             Used { .. } => No,
             // tidy-alphabetical-end
         }
diff --git a/compiler/rustc_attr_parsing/messages.ftl b/compiler/rustc_attr_parsing/messages.ftl
index 8d0ead63a8d82..35ff48cb5f24b 100644
--- a/compiler/rustc_attr_parsing/messages.ftl
+++ b/compiler/rustc_attr_parsing/messages.ftl
@@ -136,6 +136,9 @@ attr_parsing_unrecognized_repr_hint =
 attr_parsing_unstable_cfg_target_compact =
     compact `cfg(target(..))` is experimental and subject to change
 
+attr_parsing_unstable_feature_bound_incompatible_stability = Item annotated with `#[unstable_feature_bound]` should not be stable
+    .help = If this item is meant to be stable, do not use any functions annotated with `#[unstable_feature_bound]`. Otherwise, mark this item as unstable with `#[unstable]`
+
 attr_parsing_unsupported_literal_cfg_boolean =
     literal in `cfg` predicate value must be a boolean
 attr_parsing_unsupported_literal_cfg_string =
diff --git a/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs b/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
index 1c51c3eee4ef1..a6bd2306ec508 100644
--- a/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs
@@ -27,6 +27,26 @@ impl<S: Stage> CombineAttributeParser<S> for AllowInternalUnstableParser {
     }
 }
 
+pub(crate) struct UnstableFeatureBoundParser;
+impl<S: Stage> CombineAttributeParser<S> for UnstableFeatureBoundParser {
+    const PATH: &'static [rustc_span::Symbol] = &[sym::unstable_feature_bound];
+    type Item = (Symbol, Span);
+    const CONVERT: ConvertFn<Self::Item> = |items, _| AttributeKind::UnstableFeatureBound(items);
+    const TEMPLATE: AttributeTemplate = template!(Word, List: "feat1, feat2, ...");
+
+    fn extend<'c>(
+        cx: &'c mut AcceptContext<'_, '_, S>,
+        args: &'c ArgParser<'_>,
+    ) -> impl IntoIterator<Item = Self::Item> {
+        if !cx.features().staged_api() {
+            cx.emit_err(session_diagnostics::StabilityOutsideStd { span: cx.attr_span });
+        }
+        parse_unstable(cx, args, <Self as CombineAttributeParser<S>>::PATH[0])
+            .into_iter()
+            .zip(iter::repeat(cx.attr_span))
+    }
+}
+
 pub(crate) struct AllowConstFnUnstableParser;
 impl<S: Stage> CombineAttributeParser<S> for AllowConstFnUnstableParser {
     const PATH: &[Symbol] = &[sym::rustc_allow_const_fn_unstable];
diff --git a/compiler/rustc_attr_parsing/src/attributes/stability.rs b/compiler/rustc_attr_parsing/src/attributes/stability.rs
index 6bccd0042a80d..8f405e5aad972 100644
--- a/compiler/rustc_attr_parsing/src/attributes/stability.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/stability.rs
@@ -98,6 +98,16 @@ impl<S: Stage> AttributeParser<S> for StabilityParser {
             }
         }
 
+        if let Some((Stability { level: StabilityLevel::Stable { .. }, .. }, _)) = self.stability {
+            for other_attr in cx.all_attrs {
+                if other_attr.word_is(sym::unstable_feature_bound) {
+                    cx.emit_err(session_diagnostics::UnstableFeatureBoundIncompatibleStability {
+                        span: cx.target_span,
+                    });
+                }
+            }
+        }
+
         let (stability, span) = self.stability?;
 
         Some(AttributeKind::Stability { stability, span })
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index 1f6675b4c5a8a..390246239ed16 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -13,7 +13,9 @@ use rustc_hir::{AttrArgs, AttrItem, AttrPath, Attribute, HashIgnoredAttrId, HirI
 use rustc_session::Session;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym};
 
-use crate::attributes::allow_unstable::{AllowConstFnUnstableParser, AllowInternalUnstableParser};
+use crate::attributes::allow_unstable::{
+    AllowConstFnUnstableParser, AllowInternalUnstableParser, UnstableFeatureBoundParser,
+};
 use crate::attributes::codegen_attrs::{
     ColdParser, ExportNameParser, NakedParser, NoMangleParser, OmitGdbPrettyPrinterSectionParser,
     OptimizeParser, TargetFeatureParser, TrackCallerParser, UsedParser,
@@ -133,6 +135,7 @@ attribute_parsers!(
         Combine<AllowInternalUnstableParser>,
         Combine<ReprParser>,
         Combine<TargetFeatureParser>,
+        Combine<UnstableFeatureBoundParser>,
         // tidy-alphabetical-end
 
         // tidy-alphabetical-start
diff --git a/compiler/rustc_attr_parsing/src/session_diagnostics.rs b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
index 97bf3d1c54955..5b0bf0e6662f0 100644
--- a/compiler/rustc_attr_parsing/src/session_diagnostics.rs
+++ b/compiler/rustc_attr_parsing/src/session_diagnostics.rs
@@ -503,6 +503,14 @@ pub(crate) struct UnrecognizedReprHint {
     pub span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(attr_parsing_unstable_feature_bound_incompatible_stability)]
+#[help]
+pub(crate) struct UnstableFeatureBoundIncompatibleStability {
+    #[primary_span]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(attr_parsing_naked_functions_incompatible_attribute, code = E0736)]
 pub(crate) struct NakedFunctionIncompatibleAttribute {
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 7d9915d7f68b7..e2827f227abf8 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -683,6 +683,10 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         template!(List: r#"feature = "name", reason = "...", issue = "N""#), DuplicatesOk,
         EncodeCrossCrate::Yes
     ),
+    ungated!(
+        unstable_feature_bound, Normal, template!(Word, List: "feat1, feat2, ..."),
+        DuplicatesOk, EncodeCrossCrate::No,
+    ),
     ungated!(
         rustc_const_unstable, Normal, template!(List: r#"feature = "name""#),
         DuplicatesOk, EncodeCrossCrate::Yes
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 607028f4d9aef..14ec82ede1c5f 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -2212,12 +2212,16 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
         let implied_obligations = traits::elaborate(tcx, predicates_with_span);
 
         for (pred, obligation_span) in implied_obligations {
-            // We lower empty bounds like `Vec<dyn Copy>:` as
-            // `WellFormed(Vec<dyn Copy>)`, which will later get checked by
-            // regular WF checking
-            if let ty::ClauseKind::WellFormed(..) = pred.kind().skip_binder() {
-                continue;
+            match pred.kind().skip_binder() {
+                // We lower empty bounds like `Vec<dyn Copy>:` as
+                // `WellFormed(Vec<dyn Copy>)`, which will later get checked by
+                // regular WF checking
+                ty::ClauseKind::WellFormed(..)
+                // Unstable feature goals cannot be proven in an empty environment so skip them
+                | ty::ClauseKind::UnstableFeature(..) => continue,
+                _ => {}
             }
+
             // Match the existing behavior.
             if pred.is_global() && !pred.has_type_flags(TypeFlags::HAS_BINDER_VARS) {
                 let pred = self.normalize(span, None, pred);
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index a93e58b101fe5..6c502713ef5b9 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -764,6 +764,7 @@ pub(super) fn assert_only_contains_predicates_from<'tcx>(
                     ty::ClauseKind::RegionOutlives(_)
                     | ty::ClauseKind::ConstArgHasType(_, _)
                     | ty::ClauseKind::WellFormed(_)
+                    | ty::ClauseKind::UnstableFeature(_)
                     | ty::ClauseKind::ConstEvaluatable(_) => {
                         bug!(
                             "unexpected non-`Self` predicate when computing \
@@ -791,6 +792,7 @@ pub(super) fn assert_only_contains_predicates_from<'tcx>(
                     | ty::ClauseKind::ConstArgHasType(_, _)
                     | ty::ClauseKind::WellFormed(_)
                     | ty::ClauseKind::ConstEvaluatable(_)
+                    | ty::ClauseKind::UnstableFeature(_)
                     | ty::ClauseKind::HostEffect(..) => {
                         bug!(
                             "unexpected non-`Self` predicate when computing \
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index 574d19a5aa5a4..0043f0c71176a 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -499,6 +499,7 @@ fn trait_specialization_kind<'tcx>(
         | ty::ClauseKind::ConstArgHasType(..)
         | ty::ClauseKind::WellFormed(_)
         | ty::ClauseKind::ConstEvaluatable(..)
+        | ty::ClauseKind::UnstableFeature(_)
         | ty::ClauseKind::HostEffect(..) => None,
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/outlives/explicit.rs b/compiler/rustc_hir_analysis/src/outlives/explicit.rs
index 2c1d443f9512f..d3a57a4d8e5d3 100644
--- a/compiler/rustc_hir_analysis/src/outlives/explicit.rs
+++ b/compiler/rustc_hir_analysis/src/outlives/explicit.rs
@@ -54,6 +54,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> {
                     | ty::ClauseKind::ConstArgHasType(_, _)
                     | ty::ClauseKind::WellFormed(_)
                     | ty::ClauseKind::ConstEvaluatable(_)
+                    | ty::ClauseKind::UnstableFeature(_)
                     | ty::ClauseKind::HostEffect(..) => {}
                 }
             }
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs
index e4c62bf027bd3..367e2b6b372ae 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/inspect_obligations.rs
@@ -54,6 +54,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             | ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(..))
             | ty::PredicateKind::ConstEquate(..)
             | ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(..))
+            | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_))
             | ty::PredicateKind::Ambiguous => false,
         }
     }
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 94c93e7362749..3261327a9fda9 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -921,6 +921,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 | ty::ClauseKind::ConstArgHasType(_, _)
                 | ty::ClauseKind::WellFormed(_)
                 | ty::ClauseKind::ConstEvaluatable(_)
+                | ty::ClauseKind::UnstableFeature(_)
                 | ty::ClauseKind::HostEffect(..) => None,
             }
         });
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 255ff56f62b1d..8244f0bed4c93 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -1519,8 +1519,9 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
                     ClauseKind::TypeOutlives(..) |
                     ClauseKind::RegionOutlives(..) => "lifetime",
 
+                    ClauseKind::UnstableFeature(_)
                     // `ConstArgHasType` is never global as `ct` is always a param
-                    ClauseKind::ConstArgHasType(..)
+                    | ClauseKind::ConstArgHasType(..)
                     // Ignore projections, as they can only be global
                     // if the trait bound is global
                     | ClauseKind::Projection(..)
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 98b2ce01d89b2..915b062417f2f 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -137,6 +137,7 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     type FnInputTys = &'tcx [Ty<'tcx>];
     type ParamTy = ParamTy;
     type BoundTy = ty::BoundTy;
+    type Symbol = Symbol;
 
     type PlaceholderTy = ty::PlaceholderType;
     type ErrorGuaranteed = ErrorGuaranteed;
@@ -833,6 +834,13 @@ impl<'tcx> rustc_type_ir::inherent::Features<TyCtxt<'tcx>> for &'tcx rustc_featu
     fn associated_const_equality(self) -> bool {
         self.associated_const_equality()
     }
+
+    fn feature_bound_holds_in_crate(self, symbol: Symbol) -> bool {
+        // We don't consider feature bounds to hold in the crate when `staged_api` feature is
+        // enabled, even if it is enabled through `#[feature]`.
+        // This is to prevent accidentally leaking unstable APIs to stable.
+        !self.staged_api() && self.enabled(symbol)
+    }
 }
 
 impl<'tcx> rustc_type_ir::inherent::Span<TyCtxt<'tcx>> for Span {
diff --git a/compiler/rustc_middle/src/ty/predicate.rs b/compiler/rustc_middle/src/ty/predicate.rs
index bc2ac42b6b1f8..ec2224877a8a1 100644
--- a/compiler/rustc_middle/src/ty/predicate.rs
+++ b/compiler/rustc_middle/src/ty/predicate.rs
@@ -131,6 +131,7 @@ impl<'tcx> Predicate<'tcx> {
             | PredicateKind::Clause(ClauseKind::TypeOutlives(_))
             | PredicateKind::Clause(ClauseKind::Projection(_))
             | PredicateKind::Clause(ClauseKind::ConstArgHasType(..))
+            | PredicateKind::Clause(ClauseKind::UnstableFeature(_))
             | PredicateKind::DynCompatible(_)
             | PredicateKind::Subtype(_)
             | PredicateKind::Coerce(_)
@@ -649,6 +650,7 @@ impl<'tcx> Predicate<'tcx> {
             PredicateKind::Clause(ClauseKind::Projection(..))
             | PredicateKind::Clause(ClauseKind::HostEffect(..))
             | PredicateKind::Clause(ClauseKind::ConstArgHasType(..))
+            | PredicateKind::Clause(ClauseKind::UnstableFeature(_))
             | PredicateKind::NormalizesTo(..)
             | PredicateKind::AliasRelate(..)
             | PredicateKind::Subtype(..)
@@ -670,6 +672,7 @@ impl<'tcx> Predicate<'tcx> {
             PredicateKind::Clause(ClauseKind::Trait(..))
             | PredicateKind::Clause(ClauseKind::HostEffect(..))
             | PredicateKind::Clause(ClauseKind::ConstArgHasType(..))
+            | PredicateKind::Clause(ClauseKind::UnstableFeature(_))
             | PredicateKind::NormalizesTo(..)
             | PredicateKind::AliasRelate(..)
             | PredicateKind::Subtype(..)
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index 7c48a4b0885e6..b857788b8b7e3 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -3237,6 +3237,7 @@ define_print! {
             ty::ClauseKind::ConstEvaluatable(ct) => {
                 p!("the constant `", print(ct), "` can be evaluated")
             }
+            ty::ClauseKind::UnstableFeature(symbol) => p!("unstable feature: ", write("`{}`", symbol)),
         }
     }
 
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
index b42587618b57b..ce9b794d40d30 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
@@ -22,6 +22,7 @@ use crate::delegate::SolverDelegate;
 use crate::placeholder::BoundVarReplacer;
 use crate::solve::inspect::{self, ProofTreeBuilder};
 use crate::solve::search_graph::SearchGraph;
+use crate::solve::ty::may_use_unstable_feature;
 use crate::solve::{
     CanonicalInput, Certainty, FIXPOINT_STEP_LIMIT, Goal, GoalEvaluation, GoalEvaluationKind,
     GoalSource, GoalStalledOn, HasChanged, NestedNormalizationGoals, NoSolution, QueryInput,
@@ -550,6 +551,9 @@ where
                 ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(ct, ty)) => {
                     self.compute_const_arg_has_type_goal(Goal { param_env, predicate: (ct, ty) })
                 }
+                ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(symbol)) => {
+                    self.compute_unstable_feature_goal(param_env, symbol)
+                }
                 ty::PredicateKind::Subtype(predicate) => {
                     self.compute_subtype_goal(Goal { param_env, predicate })
                 }
@@ -1177,6 +1181,14 @@ where
     ) -> T {
         BoundVarReplacer::replace_bound_vars(&**self.delegate, universes, t).0
     }
+
+    pub(super) fn may_use_unstable_feature(
+        &self,
+        param_env: I::ParamEnv,
+        symbol: I::Symbol,
+    ) -> bool {
+        may_use_unstable_feature(&**self.delegate, param_env, symbol)
+    }
 }
 
 /// Eagerly replace aliases with inference variables, emitting `AliasRelate`
diff --git a/compiler/rustc_next_trait_solver/src/solve/mod.rs b/compiler/rustc_next_trait_solver/src/solve/mod.rs
index e68ea22c7a27b..5ea3f0d10617d 100644
--- a/compiler/rustc_next_trait_solver/src/solve/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/mod.rs
@@ -148,6 +148,20 @@ where
         }
     }
 
+    fn compute_unstable_feature_goal(
+        &mut self,
+        param_env: <I as Interner>::ParamEnv,
+        symbol: <I as Interner>::Symbol,
+    ) -> QueryResult<I> {
+        if self.may_use_unstable_feature(param_env, symbol) {
+            self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+        } else {
+            self.evaluate_added_goals_and_make_canonical_response(Certainty::Maybe(
+                MaybeCause::Ambiguity,
+            ))
+        }
+    }
+
     #[instrument(level = "trace", skip(self))]
     fn compute_const_evaluatable_goal(
         &mut self,
diff --git a/compiler/rustc_passes/messages.ftl b/compiler/rustc_passes/messages.ftl
index 3418d997b834f..500b4279588af 100644
--- a/compiler/rustc_passes/messages.ftl
+++ b/compiler/rustc_passes/messages.ftl
@@ -667,6 +667,10 @@ passes_rustc_std_internal_symbol =
     attribute should be applied to functions or statics
     .label = not a function or static
 
+passes_rustc_unstable_feature_bound =
+    attribute should be applied to `impl` or free function outside of any `impl` or trait
+    .label = not an `impl` or free function
+
 passes_should_be_applied_to_fn =
     attribute should be applied to a function definition
     .label = {$on_crate ->
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 820255afe274d..89000ab2619a2 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -247,6 +247,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 &Attribute::Parsed(AttributeKind::FfiPure(attr_span)) => {
                     self.check_ffi_pure(attr_span, attrs, target)
                 }
+                Attribute::Parsed(AttributeKind::UnstableFeatureBound(syms)) => {
+                    self.check_unstable_feature_bound(syms.first().unwrap().1, span, target)
+                }
                 Attribute::Parsed(
                     AttributeKind::BodyStability { .. }
                     | AttributeKind::ConstStabilityIndirect
@@ -2267,6 +2270,47 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
+    fn check_unstable_feature_bound(&self, attr_span: Span, span: Span, target: Target) {
+        match target {
+            // FIXME(staged_api): There's no reason we can't support more targets here. We're just
+            // being conservative to begin with.
+            Target::Fn | Target::Impl => {}
+            Target::ExternCrate
+            | Target::Use
+            | Target::Static
+            | Target::Const
+            | Target::Closure
+            | Target::Mod
+            | Target::ForeignMod
+            | Target::GlobalAsm
+            | Target::TyAlias
+            | Target::Enum
+            | Target::Variant
+            | Target::Struct
+            | Target::Field
+            | Target::Union
+            | Target::Trait
+            | Target::TraitAlias
+            | Target::Expression
+            | Target::Statement
+            | Target::Arm
+            | Target::AssocConst
+            | Target::Method(_)
+            | Target::AssocTy
+            | Target::ForeignFn
+            | Target::ForeignStatic
+            | Target::ForeignTy
+            | Target::GenericParam(_)
+            | Target::MacroDef
+            | Target::Param
+            | Target::PatField
+            | Target::ExprField
+            | Target::WherePredicate => {
+                self.tcx.dcx().emit_err(errors::RustcUnstableFeatureBound { attr_span, span });
+            }
+        }
+    }
+
     fn check_rustc_std_internal_symbol(&self, attr_span: Span, span: Span, target: Target) {
         match target {
             Target::Fn | Target::Static | Target::ForeignFn | Target::ForeignStatic => {}
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index 093a2b38804fd..37330c0ed6ebf 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -686,6 +686,15 @@ pub(crate) struct RustcAllowConstFnUnstable {
     pub span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(passes_rustc_unstable_feature_bound)]
+pub(crate) struct RustcUnstableFeatureBound {
+    #[primary_span]
+    pub attr_span: Span,
+    #[label]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(passes_rustc_std_internal_symbol)]
 pub(crate) struct RustcStdInternalSymbol {
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index adda94fda8f0b..e5530d526866a 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -802,12 +802,28 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
                     // FIXME(jdonszelmann): make it impossible to miss the or_else in the typesystem
                     let const_stab = attrs::find_attr!(attrs, AttributeKind::ConstStability{stability, ..} => *stability);
 
+                    let unstable_feature_stab =
+                        find_attr!(attrs, AttributeKind::UnstableFeatureBound(i) => i)
+                            .map(|i| i.as_slice())
+                            .unwrap_or_default();
+
                     // If this impl block has an #[unstable] attribute, give an
                     // error if all involved types and traits are stable, because
                     // it will have no effect.
                     // See: https://github.com/rust-lang/rust/issues/55436
+                    //
+                    // The exception is when there are both  #[unstable_feature_bound(..)] and
+                    //  #![unstable(feature = "..", issue = "..")] that have the same symbol because
+                    // that can effectively mark an impl as unstable.
+                    //
+                    // For example:
+                    // ```
+                    // #[unstable_feature_bound(feat_foo)]
+                    // #[unstable(feature = "feat_foo", issue = "none")]
+                    // impl Foo for Bar {}
+                    // ```
                     if let Some((
-                        Stability { level: attrs::StabilityLevel::Unstable { .. }, .. },
+                        Stability { level: attrs::StabilityLevel::Unstable { .. }, feature },
                         span,
                     )) = stab
                     {
@@ -815,9 +831,21 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
                         c.visit_ty_unambig(self_ty);
                         c.visit_trait_ref(t);
 
+                        // Skip the lint if the impl is marked as unstable using
+                        // #[unstable_feature_bound(..)]
+                        let mut unstable_feature_bound_in_effect = false;
+                        for (unstable_bound_feat_name, _) in unstable_feature_stab {
+                            if *unstable_bound_feat_name == feature {
+                                unstable_feature_bound_in_effect = true;
+                            }
+                        }
+
                         // do not lint when the trait isn't resolved, since resolution error should
                         // be fixed first
-                        if t.path.res != Res::Err && c.fully_stable {
+                        if t.path.res != Res::Err
+                            && c.fully_stable
+                            && !unstable_feature_bound_in_effect
+                        {
                             self.tcx.emit_node_span_lint(
                                 INEFFECTIVE_UNSTABLE_TRAIT_IMPL,
                                 item.hir_id(),
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index ab2433234aa90..80c13e44d7d8e 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -156,6 +156,7 @@ where
             }
             ty::ClauseKind::ConstEvaluatable(ct) => ct.visit_with(self),
             ty::ClauseKind::WellFormed(term) => term.visit_with(self),
+            ty::ClauseKind::UnstableFeature(_) => V::Result::output(),
         }
     }
 
diff --git a/compiler/rustc_public/src/unstable/convert/stable/ty.rs b/compiler/rustc_public/src/unstable/convert/stable/ty.rs
index 75c2978878751..6b226b8a24d12 100644
--- a/compiler/rustc_public/src/unstable/convert/stable/ty.rs
+++ b/compiler/rustc_public/src/unstable/convert/stable/ty.rs
@@ -764,6 +764,9 @@ impl<'tcx> Stable<'tcx> for ty::ClauseKind<'tcx> {
             ClauseKind::HostEffect(..) => {
                 todo!()
             }
+            ClauseKind::UnstableFeature(_) => {
+                todo!()
+            }
         }
     }
 }
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index 0118cdb1fc274..9097b27b86c4c 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -205,6 +205,46 @@ pub fn add_feature_diagnostics_for_issue<G: EmissionGuarantee>(
     }
 }
 
+/// This is only used by unstable_feature_bound as it does not have issue number information for now.
+/// This is basically the same as `feature_err_issue`
+/// but without the feature issue note. If we can do a lookup for issue number from feature name,
+/// then we should directly use `feature_err_issue` for ambiguity error of
+/// `#[unstable_feature_bound]`.
+#[track_caller]
+pub fn feature_err_unstable_feature_bound(
+    sess: &Session,
+    feature: Symbol,
+    span: impl Into<MultiSpan>,
+    explain: impl Into<DiagMessage>,
+) -> Diag<'_> {
+    let span = span.into();
+
+    // Cancel an earlier warning for this same error, if it exists.
+    if let Some(span) = span.primary_span() {
+        if let Some(err) = sess.dcx().steal_non_err(span, StashKey::EarlySyntaxWarning) {
+            err.cancel()
+        }
+    }
+
+    let mut err = sess.dcx().create_err(FeatureGateError { span, explain: explain.into() });
+
+    // #23973: do not suggest `#![feature(...)]` if we are in beta/stable
+    if sess.psess.unstable_features.is_nightly_build() {
+        err.subdiagnostic(FeatureDiagnosticHelp { feature });
+
+        if feature == sym::rustc_attrs {
+            // We're unlikely to stabilize something out of `rustc_attrs`
+            // without at least renaming it, so pointing out how old
+            // the compiler is will do little good.
+        } else if sess.opts.unstable_opts.ui_testing {
+            err.subdiagnostic(SuggestUpgradeCompiler::ui_testing());
+        } else if let Some(suggestion) = SuggestUpgradeCompiler::new() {
+            err.subdiagnostic(suggestion);
+        }
+    }
+    err
+}
+
 /// Info about a parsing session.
 pub struct ParseSess {
     dcx: DiagCtxt,
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 8b12edf426c1b..bd34055f85133 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -2284,6 +2284,7 @@ symbols! {
         unsized_locals,
         unsized_tuple_coercion,
         unstable,
+        unstable_feature_bound,
         unstable_location_reason_default: "this crate is being loaded from the sysroot, an \
                           unstable location; did you mean to load this crate \
                           from crates.io via `Cargo.toml` instead?",
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs
index 712e88300fff9..98f67257fd137 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/ambiguity.rs
@@ -12,6 +12,7 @@ use rustc_infer::traits::{
     Obligation, ObligationCause, ObligationCauseCode, PolyTraitObligation, PredicateObligation,
 };
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable as _, TypeVisitableExt as _};
+use rustc_session::parse::feature_err_unstable_feature_bound;
 use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span};
 use tracing::{debug, instrument};
 
@@ -611,6 +612,30 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 )
                 .with_span_label(span, format!("cannot normalize `{alias}`"))
             }
+            ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(sym)) => {
+                if let Some(e) = self.tainted_by_errors() {
+                    return e;
+                }
+
+                let mut err;
+
+                if self.tcx.features().staged_api() {
+                    err = self.dcx().struct_span_err(
+                        span,
+                        format!("unstable feature `{sym}` is used without being enabled."),
+                    );
+
+                    err.help(format!("The feature can be enabled by marking the current item with `#[unstable_feature_bound({sym})]`"));
+                } else {
+                    err = feature_err_unstable_feature_bound(
+                        &self.tcx.sess,
+                        sym,
+                        span,
+                        format!("use of unstable library feature `{sym}`"),
+                    );
+                }
+                err
+            }
 
             _ => {
                 if let Some(e) = self.tainted_by_errors() {
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
index cd3e6c4bc543f..1ac309da101f1 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
@@ -647,6 +647,8 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                     | ty::PredicateKind::ConstEquate { .. }
                     // Ambiguous predicates should never error
                     | ty::PredicateKind::Ambiguous
+                    // We never return Err when proving UnstableFeature goal.
+                    | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature{ .. })
                     | ty::PredicateKind::NormalizesTo { .. }
                     | ty::PredicateKind::AliasRelate { .. }
                     | ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType { .. }) => {
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 3ae908ec16b8e..759db1d18c013 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -800,6 +800,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                 // FIXME(generic_const_exprs): you can absolutely add this as a where clauses
                 | ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(..))
                 | ty::PredicateKind::Coerce(..)
+                | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_))
                 | ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(..)) => {}
                 ty::PredicateKind::Ambiguous => return false,
             };
diff --git a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
index 9a4f3887bbb59..ea1eed9572330 100644
--- a/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
+++ b/compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs
@@ -238,6 +238,7 @@ fn predicate_references_self<'tcx>(
         // FIXME(generic_const_exprs): this can mention `Self`
         | ty::ClauseKind::ConstEvaluatable(..)
         | ty::ClauseKind::HostEffect(..)
+        | ty::ClauseKind::UnstableFeature(_)
          => None,
     }
 }
@@ -278,6 +279,7 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
         | ty::ClauseKind::ConstArgHasType(_, _)
         | ty::ClauseKind::WellFormed(_)
         | ty::ClauseKind::ConstEvaluatable(_)
+        | ty::ClauseKind::UnstableFeature(_)
         | ty::ClauseKind::HostEffect(..) => false,
     })
 }
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index 64a51e0550ba1..2b5a41ef5a71b 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -11,7 +11,9 @@ use rustc_infer::traits::{
 use rustc_middle::bug;
 use rustc_middle::ty::abstract_const::NotConstEvaluatable;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
-use rustc_middle::ty::{self, Binder, Const, GenericArgsRef, TypeVisitableExt, TypingMode};
+use rustc_middle::ty::{
+    self, Binder, Const, GenericArgsRef, TypeVisitableExt, TypingMode, may_use_unstable_feature,
+};
 use thin_vec::{ThinVec, thin_vec};
 use tracing::{debug, debug_span, instrument};
 
@@ -404,6 +406,9 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
                 ty::PredicateKind::AliasRelate(..) => {
                     bug!("AliasRelate is only used by the new solver")
                 }
+                ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_)) => {
+                   unreachable!("unexpected higher ranked `UnstableFeature` goal")
+                }
             },
             Some(pred) => match pred {
                 ty::PredicateKind::Clause(ty::ClauseKind::Trait(data)) => {
@@ -767,6 +772,13 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
                         }
                     }
                 }
+                ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(symbol)) => {
+                    if may_use_unstable_feature(self.selcx.infcx, obligation.param_env, symbol) {
+                        ProcessResult::Changed(Default::default())
+                    } else {
+                        ProcessResult::Unchanged
+                    }
+                }
             },
         }
     }
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
index e294f7839aac7..7540cbe3fd1a4 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
@@ -110,6 +110,7 @@ pub fn compute_implied_outlives_bounds_inner<'tcx>(
                 | ty::PredicateKind::ConstEquate(..)
                 | ty::PredicateKind::Ambiguous
                 | ty::PredicateKind::NormalizesTo(..)
+                | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_))
                 | ty::PredicateKind::AliasRelate(..) => {}
 
                 // We need to search through *all* WellFormed predicates
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 2e65750db25de..10bcf861d35b4 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -28,7 +28,7 @@ use rustc_middle::ty::error::TypeErrorToStringExt;
 use rustc_middle::ty::print::{PrintTraitRefExt as _, with_no_trimmed_paths};
 use rustc_middle::ty::{
     self, DeepRejectCtxt, GenericArgsRef, PolyProjectionPredicate, SizedTraitKind, Ty, TyCtxt,
-    TypeFoldable, TypeVisitableExt, TypingMode, Upcast, elaborate,
+    TypeFoldable, TypeVisitableExt, TypingMode, Upcast, elaborate, may_use_unstable_feature,
 };
 use rustc_span::{Symbol, sym};
 use tracing::{debug, instrument, trace};
@@ -832,6 +832,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     }
                 }
 
+                ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(symbol)) => {
+                    if may_use_unstable_feature(self.infcx, obligation.param_env, symbol) {
+                        Ok(EvaluatedToOk)
+                    } else {
+                        Ok(EvaluatedToAmbig)
+                    }
+                }
+
                 ty::PredicateKind::Clause(ty::ClauseKind::ConstEvaluatable(uv)) => {
                     match const_evaluatable::is_const_evaluatable(
                         self.infcx,
diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs
index 141454bfe3754..25cd7787a3496 100644
--- a/compiler/rustc_trait_selection/src/traits/util.rs
+++ b/compiler/rustc_trait_selection/src/traits/util.rs
@@ -80,6 +80,7 @@ pub fn expand_trait_aliases<'tcx>(
             | ty::ClauseKind::ConstArgHasType(_, _)
             | ty::ClauseKind::WellFormed(_)
             | ty::ClauseKind::ConstEvaluatable(_)
+            | ty::ClauseKind::UnstableFeature(_)
             | ty::ClauseKind::HostEffect(..) => {}
         }
     }
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index fed9f254cdf83..adce9850b594c 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -197,6 +197,7 @@ pub fn clause_obligations<'tcx>(
         ty::ClauseKind::ConstEvaluatable(ct) => {
             wf.add_wf_preds_for_term(ct.into());
         }
+        ty::ClauseKind::UnstableFeature(_) => {}
     }
 
     wf.normalize(infcx)
@@ -1095,6 +1096,7 @@ pub fn object_region_bounds<'tcx>(
                 | ty::ClauseKind::Projection(_)
                 | ty::ClauseKind::ConstArgHasType(_, _)
                 | ty::ClauseKind::WellFormed(_)
+                | ty::ClauseKind::UnstableFeature(_)
                 | ty::ClauseKind::ConstEvaluatable(_) => None,
             }
         })
diff --git a/compiler/rustc_traits/src/normalize_erasing_regions.rs b/compiler/rustc_traits/src/normalize_erasing_regions.rs
index 68ff66bbce7cf..c1b848a2e79da 100644
--- a/compiler/rustc_traits/src/normalize_erasing_regions.rs
+++ b/compiler/rustc_traits/src/normalize_erasing_regions.rs
@@ -57,6 +57,7 @@ fn not_outlives_predicate(p: ty::Predicate<'_>) -> bool {
         | ty::PredicateKind::Clause(ty::ClauseKind::Projection(..))
         | ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(..))
         | ty::PredicateKind::Clause(ty::ClauseKind::ConstArgHasType(..))
+        | ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_))
         | ty::PredicateKind::NormalizesTo(..)
         | ty::PredicateKind::AliasRelate(..)
         | ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(..))
diff --git a/compiler/rustc_type_ir/src/elaborate.rs b/compiler/rustc_type_ir/src/elaborate.rs
index 7ffcf7b5d9654..380082487579e 100644
--- a/compiler/rustc_type_ir/src/elaborate.rs
+++ b/compiler/rustc_type_ir/src/elaborate.rs
@@ -234,6 +234,9 @@ impl<I: Interner, O: Elaboratable<I>> Elaborator<I, O> {
             ty::ClauseKind::ConstArgHasType(..) => {
                 // Nothing to elaborate
             }
+            ty::ClauseKind::UnstableFeature(_) => {
+                // Nothing to elaborate
+            }
         }
     }
 }
diff --git a/compiler/rustc_type_ir/src/flags.rs b/compiler/rustc_type_ir/src/flags.rs
index 37cc2baa402a0..a231908f874c2 100644
--- a/compiler/rustc_type_ir/src/flags.rs
+++ b/compiler/rustc_type_ir/src/flags.rs
@@ -401,7 +401,6 @@ impl<I: Interner> FlagComputation<I> {
                 self.add_const(expected);
                 self.add_const(found);
             }
-            ty::PredicateKind::Ambiguous => {}
             ty::PredicateKind::NormalizesTo(ty::NormalizesTo { alias, term }) => {
                 self.add_alias_term(alias);
                 self.add_term(term);
@@ -410,6 +409,8 @@ impl<I: Interner> FlagComputation<I> {
                 self.add_term(t1);
                 self.add_term(t2);
             }
+            ty::PredicateKind::Clause(ty::ClauseKind::UnstableFeature(_sym)) => {}
+            ty::PredicateKind::Ambiguous => {}
         }
     }
 
diff --git a/compiler/rustc_type_ir/src/infer_ctxt.rs b/compiler/rustc_type_ir/src/infer_ctxt.rs
index 6c77a90250a4a..e86a2305e2334 100644
--- a/compiler/rustc_type_ir/src/infer_ctxt.rs
+++ b/compiler/rustc_type_ir/src/infer_ctxt.rs
@@ -285,3 +285,40 @@ pub trait InferCtxtLike: Sized {
 
     fn reset_opaque_types(&self);
 }
+
+pub fn may_use_unstable_feature<'a, I: Interner, Infcx>(
+    infcx: &'a Infcx,
+    param_env: I::ParamEnv,
+    symbol: I::Symbol,
+) -> bool
+where
+    Infcx: InferCtxtLike<Interner = I>,
+{
+    // Iterate through all goals in param_env to find the one that has the same symbol.
+    for pred in param_env.caller_bounds().iter() {
+        if let ty::ClauseKind::UnstableFeature(sym) = pred.kind().skip_binder() {
+            if sym == symbol {
+                return true;
+            }
+        }
+    }
+
+    // During codegen we must assume that all feature bounds hold as we may be
+    // monomorphizing a body from an upstream crate which had an unstable feature
+    // enabled that we do not.
+    //
+    // Coherence should already report overlap errors involving unstable impls
+    // as the affected code would otherwise break when stabilizing this feature.
+    // It is also easily possible to accidentally cause unsoundness this way as
+    // we have to always enable unstable impls during codegen.
+    //
+    // Return ambiguity can also prevent people from writing code which depends on inference guidance
+    // that might no longer work after the impl is stabilised,
+    // tests/ui/unstable-feature-bound/unstable_impl_method_selection.rs is one of the example.
+    //
+    // Note: `feature_bound_holds_in_crate` does not consider a feature to be enabled
+    // if we are in std/core even if there is a corresponding `feature` attribute on the crate.
+
+    (infcx.typing_mode() == TypingMode::PostAnalysis)
+        || infcx.cx().features().feature_bound_holds_in_crate(symbol)
+}
diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs
index 2754d40fd36ce..0e307e15d5b4d 100644
--- a/compiler/rustc_type_ir/src/inherent.rs
+++ b/compiler/rustc_type_ir/src/inherent.rs
@@ -630,6 +630,8 @@ pub trait Features<I: Interner>: Copy {
     fn coroutine_clone(self) -> bool;
 
     fn associated_const_equality(self) -> bool;
+
+    fn feature_bound_holds_in_crate(self, symbol: I::Symbol) -> bool;
 }
 
 pub trait DefId<I: Interner>: Copy + Debug + Hash + Eq + TypeFoldable<I> {
diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs
index dd3cf1fc1811f..0ec326d21169e 100644
--- a/compiler/rustc_type_ir/src/interner.rs
+++ b/compiler/rustc_type_ir/src/interner.rs
@@ -106,6 +106,7 @@ pub trait Interner:
     type ParamTy: ParamLike;
     type BoundTy: BoundVarLike<Self>;
     type PlaceholderTy: PlaceholderLike<Self, Bound = Self::BoundTy>;
+    type Symbol: Copy + Hash + PartialEq + Eq + Debug;
 
     // Things stored inside of tys
     type ErrorGuaranteed: Copy + Debug + Hash + Eq;
diff --git a/compiler/rustc_type_ir/src/predicate_kind.rs b/compiler/rustc_type_ir/src/predicate_kind.rs
index 4e41fd16ffd76..8bc15ec4ff557 100644
--- a/compiler/rustc_type_ir/src/predicate_kind.rs
+++ b/compiler/rustc_type_ir/src/predicate_kind.rs
@@ -46,6 +46,13 @@ pub enum ClauseKind<I: Interner> {
     /// corresponding trait clause; this just enforces the *constness* of that
     /// implementation.
     HostEffect(ty::HostEffectPredicate<I>),
+
+    /// Support marking impl as unstable.
+    UnstableFeature(
+        #[type_foldable(identity)]
+        #[type_visitable(ignore)]
+        I::Symbol,
+    ),
 }
 
 #[derive_where(Clone, Copy, Hash, PartialEq, Eq; I: Interner)]
@@ -134,6 +141,9 @@ impl<I: Interner> fmt::Debug for ClauseKind<I> {
             ClauseKind::ConstEvaluatable(ct) => {
                 write!(f, "ConstEvaluatable({ct:?})")
             }
+            ClauseKind::UnstableFeature(feature_name) => {
+                write!(f, "UnstableFeature({feature_name:?})")
+            }
         }
     }
 }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index e7a1f4d8397b4..3df04091f1631 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -390,7 +390,8 @@ pub(crate) fn clean_predicate<'tcx>(
         ty::ClauseKind::ConstEvaluatable(..)
         | ty::ClauseKind::WellFormed(..)
         | ty::ClauseKind::ConstArgHasType(..)
-        // FIXME(const_trait_impl): We can probably use this `HostEffect` pred to render `[const]`.
+        | ty::ClauseKind::UnstableFeature(..)
+        // FIXME(const_trait_impl): We can probably use this `HostEffect` pred to render `~const`.
         | ty::ClauseKind::HostEffect(_) => None,
     }
 }