diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 8469f477edb..10c0ae6d374 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -28,9 +28,7 @@
 
 use metadata::csearch;
 use middle::def::*;
-use middle::infer;
 use middle::ty::{mod, Ty};
-use middle::typeck::astconv::ast_ty_to_ty;
 use middle::{def, pat_util, stability};
 use middle::const_eval::{eval_const_expr_partial, const_int, const_uint};
 use util::ppaux::{ty_to_string};
@@ -84,7 +82,7 @@ fn get_lints(&self) -> LintArray {
 
     fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
         if let ast::ExprCast(ref expr, ref ty) = e.node {
-            let t_t = ast_ty_to_ty(cx, &infer::new_infer_ctxt(cx.tcx), &**ty);
+            let t_t = ty::expr_ty(cx.tcx, e);
             if ty::expr_ty(cx.tcx, &**expr) == t_t {
                 cx.span_lint(UNUSED_TYPECASTS, ty.span, "unnecessary type cast");
             }
diff --git a/src/librustc/lint/context.rs b/src/librustc/lint/context.rs
index 8014673f759..442d3aab92d 100644
--- a/src/librustc/lint/context.rs
+++ b/src/librustc/lint/context.rs
@@ -25,18 +25,14 @@
 //! for all lint attributes.
 use self::TargetLint::*;
 
-use middle::infer;
 use middle::privacy::ExportedItems;
-use middle::subst;
 use middle::ty::{mod, Ty};
-use middle::typeck::astconv::AstConv;
 use session::{early_error, Session};
 use lint::{Level, LevelSource, Lint, LintId, LintArray, LintPass, LintPassObject};
 use lint::{Default, CommandLine, Node, Allow, Warn, Deny, Forbid};
 use lint::builtin;
 use util::nodemap::FnvHashMap;
 
-use std::rc::Rc;
 use std::cell::RefCell;
 use std::tuple::Tuple2;
 use std::mem;
@@ -541,42 +537,6 @@ fn visit_ids(&mut self, f: |&mut ast_util::IdVisitor<Context>|) {
     }
 }
 
-impl<'a, 'tcx> AstConv<'tcx> for Context<'a, 'tcx>{
-    fn tcx<'a>(&'a self) -> &'a ty::ctxt<'tcx> { self.tcx }
-
-    fn get_item_ty(&self, id: ast::DefId) -> ty::Polytype<'tcx> {
-        ty::lookup_item_type(self.tcx, id)
-    }
-
-    fn get_trait_def(&self, id: ast::DefId) -> Rc<ty::TraitDef<'tcx>> {
-        ty::lookup_trait_def(self.tcx, id)
-    }
-
-    fn ty_infer(&self, _span: Span) -> Ty<'tcx> {
-        infer::new_infer_ctxt(self.tcx).next_ty_var()
-    }
-
-    fn associated_types_of_trait_are_valid(&self, _: Ty<'tcx>, _: ast::DefId)
-                                           -> bool {
-        // FIXME(pcwalton): This is wrong.
-        true
-    }
-
-    fn associated_type_binding(&self,
-                               _: Span,
-                               _: Option<Ty<'tcx>>,
-                               trait_id: ast::DefId,
-                               associated_type_id: ast::DefId)
-                               -> Ty<'tcx> {
-        // FIXME(pcwalton): This is wrong.
-        let trait_def = self.get_trait_def(trait_id);
-        let index = ty::associated_type_parameter_index(self.tcx,
-                                                        &*trait_def,
-                                                        associated_type_id);
-        ty::mk_param(self.tcx, subst::TypeSpace, index, associated_type_id)
-    }
-}
-
 impl<'a, 'tcx, 'v> Visitor<'v> for Context<'a, 'tcx> {
     fn visit_item(&mut self, it: &ast::Item) {
         self.with_lint_attrs(it.attrs.as_slice(), |cx| {