1 files changed, 8 insertions, 4 deletions
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 533ee9bff54..d3e8f62618f 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -296,6 +296,7 @@ enum RelaxedBoundPolicy<'a> {
 enum RelaxedBoundForbiddenReason {
     TraitObjectTy,
     SuperTrait,
+    AssocTyBounds,
     LateBoundVarsInScope,
 }
 
@@ -1102,9 +1103,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         &*self.arena.alloc(self.ty(constraint.span, hir::TyKind::Err(guar)));
                     hir::AssocItemConstraintKind::Equality { term: err_ty.into() }
                 } else {
-                    // FIXME(#135229): These should be forbidden!
-                    let bounds =
-                        self.lower_param_bounds(bounds, RelaxedBoundPolicy::Allowed, itctx);
+                    let bounds = self.lower_param_bounds(
+                        bounds,
+                        RelaxedBoundPolicy::Forbidden(RelaxedBoundForbiddenReason::AssocTyBounds),
+                        itctx,
+                    );
                     hir::AssocItemConstraintKind::Bound { bounds }
                 }
             }
@@ -2117,7 +2120,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         diag.emit();
                         return;
                     }
-                    RelaxedBoundForbiddenReason::LateBoundVarsInScope => {}
+                    RelaxedBoundForbiddenReason::AssocTyBounds
+                    | RelaxedBoundForbiddenReason::LateBoundVarsInScope => {}
                 };
             }
         }