diff --git a/src/librustc/metadata/tydecode.rs b/src/librustc/metadata/tydecode.rs
index c87b09cde08..f12cc140d8a 100644
--- a/src/librustc/metadata/tydecode.rs
+++ b/src/librustc/metadata/tydecode.rs
@@ -289,7 +289,8 @@ fn parse_ty(st: @mut PState, conv: conv_did) -> ty::t {
         return ty::mk_param(st.tcx, parse_int(st) as uint, did);
       }
       's' => {
-        return ty::mk_self(st.tcx);
+        let did = parse_def(st, TypeParameter, conv);
+        return ty::mk_self(st.tcx, did);
       }
       '@' => return ty::mk_box(st.tcx, parse_mt(st, conv)),
       '~' => return ty::mk_uniq(st.tcx, parse_mt(st, conv)),
diff --git a/src/librustc/metadata/tyencode.rs b/src/librustc/metadata/tyencode.rs
index 56a96837623..880d01d1cdb 100644
--- a/src/librustc/metadata/tyencode.rs
+++ b/src/librustc/metadata/tyencode.rs
@@ -312,8 +312,10 @@ fn enc_sty(w: @io::Writer, cx: @ctxt, +st: ty::sty) {
         w.write_char('|');
         w.write_str(uint::to_str(id));
       }
-      ty::ty_self => {
+      ty::ty_self(did) => {
         w.write_char('s');
+        w.write_str((cx.ds)(did));
+        w.write_char('|');
       }
       ty::ty_type => w.write_char('Y'),
       ty::ty_opaque_closure_ptr(p) => {
diff --git a/src/librustc/middle/trans/reflect.rs b/src/librustc/middle/trans/reflect.rs
index c6bf8ff3a3a..41e63cc878e 100644
--- a/src/librustc/middle/trans/reflect.rs
+++ b/src/librustc/middle/trans/reflect.rs
@@ -297,7 +297,7 @@ pub impl Reflector {
               let extra = ~[self.c_uint(p.idx)];
               self.visit(~"param", extra)
           }
-          ty::ty_self => self.leaf(~"self"),
+          ty::ty_self(*) => self.leaf(~"self"),
           ty::ty_type => self.leaf(~"type"),
           ty::ty_opaque_box => self.leaf(~"opaque_box"),
           ty::ty_opaque_closure_ptr(ck) => {
diff --git a/src/librustc/middle/trans/type_of.rs b/src/librustc/middle/trans/type_of.rs
index 785a3183676..a7bec5547c4 100644
--- a/src/librustc/middle/trans/type_of.rs
+++ b/src/librustc/middle/trans/type_of.rs
@@ -144,7 +144,7 @@ pub fn sizing_type_of(cx: @CrateContext, t: ty::t) -> TypeRef {
             T_struct(adt::sizing_fields_of(cx, repr))
         }
 
-        ty::ty_self | ty::ty_infer(*) | ty::ty_param(*) | ty::ty_err(*) => {
+        ty::ty_self(_) | ty::ty_infer(*) | ty::ty_param(*) | ty::ty_err(*) => {
             cx.tcx.sess.bug(
                 fmt!("fictitious type %? in sizing_type_of()",
                      ty::get(t).sty))
@@ -251,7 +251,7 @@ pub fn type_of(cx: @CrateContext, t: ty::t) -> TypeRef {
                                               did,
                                               /*bad*/ copy substs.tps))
       }
-      ty::ty_self => cx.tcx.sess.unimpl(~"type_of: ty_self"),
+      ty::ty_self(*) => cx.tcx.sess.unimpl(~"type_of: ty_self"),
       ty::ty_infer(*) => cx.tcx.sess.bug(~"type_of with ty_infer"),
       ty::ty_param(*) => cx.tcx.sess.bug(~"type_of with ty_param"),
       ty::ty_err(*) => cx.tcx.sess.bug(~"type_of with ty_err")
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index fc634f91ccf..e50fd7b10cc 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -522,7 +522,8 @@ pub enum sty {
     ty_tup(~[t]),
 
     ty_param(param_ty), // type parameter
-    ty_self, // special, implicit `self` type parameter
+    ty_self(def_id), /* special, implicit `self` type parameter;
+                      * def_id is the id of the trait */
 
     ty_infer(InferTy), // something used only during inference/typeck
     ty_err, // Also only used during inference/typeck, to represent
@@ -897,7 +898,7 @@ fn mk_t_with_id(cx: ctxt, +st: sty, o_def_id: Option<ast::def_id>) -> t {
       &ty_err => flags |= has_ty_err as uint,
       &ty_param(_) => flags |= has_params as uint,
       &ty_infer(_) => flags |= needs_infer as uint,
-      &ty_self => flags |= has_self as uint,
+      &ty_self(_) => flags |= has_self as uint,
       &ty_enum(_, ref substs) | &ty_struct(_, ref substs) |
       &ty_trait(_, ref substs, _) => {
         flags |= sflags(substs);
@@ -1082,7 +1083,7 @@ pub fn mk_float_var(cx: ctxt, v: FloatVid) -> t { mk_infer(cx, FloatVar(v)) }
 
 pub fn mk_infer(cx: ctxt, +it: InferTy) -> t { mk_t(cx, ty_infer(it)) }
 
-pub fn mk_self(cx: ctxt) -> t { mk_t(cx, ty_self) }
+pub fn mk_self(cx: ctxt, did: ast::def_id) -> t { mk_t(cx, ty_self(did)) }
 
 pub fn mk_param(cx: ctxt, n: uint, k: def_id) -> t {
     mk_t(cx, ty_param(param_ty { idx: n, def_id: k }))
@@ -1163,7 +1164,7 @@ pub fn maybe_walk_ty(ty: t, f: &fn(t) -> bool) {
     if !f(ty) { return; }
     match get(ty).sty {
       ty_nil | ty_bot | ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
-      ty_estr(_) | ty_type | ty_opaque_box | ty_self |
+      ty_estr(_) | ty_type | ty_opaque_box | ty_self(_) |
       ty_opaque_closure_ptr(_) | ty_infer(_) | ty_param(_) | ty_err => {
       }
       ty_box(ref tm) | ty_evec(ref tm, _) | ty_unboxed_vec(ref tm) |
@@ -1250,7 +1251,7 @@ fn fold_sty(sty: &sty, fldop: &fn(t) -> t) -> sty {
         }
         ty_nil | ty_bot | ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
         ty_estr(_) | ty_type | ty_opaque_closure_ptr(_) | ty_err |
-        ty_opaque_box | ty_infer(_) | ty_param(*) | ty_self => {
+        ty_opaque_box | ty_infer(_) | ty_param(*) | ty_self(_) => {
             /*bad*/copy *sty
         }
     }
@@ -1362,7 +1363,7 @@ pub fn subst_tps(cx: ctxt, tps: &[t], self_ty_opt: Option<t>, typ: t) -> t {
     if self_ty_opt.is_none() && !tbox_has_flag(tb, has_params) { return typ; }
     match tb.sty {
         ty_param(p) => tps[p.idx],
-        ty_self => {
+        ty_self(_) => {
             match self_ty_opt {
                 None => cx.sess.bug(~"ty_self unexpected here"),
                 Some(self_ty) => {
@@ -1424,7 +1425,7 @@ pub fn subst(cx: ctxt,
         if !tbox_has_flag(tb, needs_subst) { return typ; }
         match tb.sty {
           ty_param(p) => substs.tps[p.idx],
-          ty_self => substs.self_ty.get(),
+          ty_self(_) => substs.self_ty.get(),
           _ => {
             fold_regions_and_ty(
                 cx, typ,
@@ -2002,7 +2003,7 @@ pub fn type_contents(cx: ctxt, ty: t) -> TypeContents {
                     cx, cx.ty_param_bounds.get(&p.def_id.node))
             }
 
-            ty_self => {
+            ty_self(_) => {
                 // Currently, self is not bounded, so we must assume the
                 // worst.  But in the future we should examine the super
                 // traits.
@@ -2159,7 +2160,7 @@ pub fn type_contents(cx: ctxt, ty: t) -> TypeContents {
                     v.args.foldl(0, |s, a| *s + type_size(cx, *a))))
           }
 
-          ty_param(_) | ty_self => {
+          ty_param(_) | ty_self(_) => {
             1
           }
 
@@ -2220,7 +2221,7 @@ pub fn is_instantiable(cx: ctxt, r_ty: t) -> bool {
           ty_infer(_) |
           ty_err |
           ty_param(_) |
-          ty_self |
+          ty_self(_) |
           ty_type |
           ty_opaque_box |
           ty_opaque_closure_ptr(_) |
@@ -2655,7 +2656,7 @@ impl to_bytes::IterBytes for sty {
           ty_bare_fn(ref ft) =>
           to_bytes::iter_bytes_2(&12u8, ft, lsb0, f),
 
-          ty_self => 13u8.iter_bytes(lsb0, f),
+          ty_self(ref did) => to_bytes::iter_bytes_2(&13u8, did, lsb0, f),
 
           ty_infer(ref v) =>
           to_bytes::iter_bytes_2(&14u8, v, lsb0, f),
@@ -3341,7 +3342,7 @@ pub fn ty_sort_str(cx: ctxt, t: t) -> ~str {
       ty_infer(IntVar(_)) => ~"integral variable",
       ty_infer(FloatVar(_)) => ~"floating-point variable",
       ty_param(_) => ~"type parameter",
-      ty_self => ~"self",
+      ty_self(_) => ~"self",
       ty_err => ~"type error"
     }
 }
diff --git a/src/librustc/middle/typeck/astconv.rs b/src/librustc/middle/typeck/astconv.rs
index b49c8c2bff8..e259fdaf400 100644
--- a/src/librustc/middle/typeck/astconv.rs
+++ b/src/librustc/middle/typeck/astconv.rs
@@ -64,7 +64,7 @@ use middle::typeck::{CrateCtxt, write_substs_to_tcx, write_ty_to_tcx};
 
 use core::result;
 use core::vec;
-use syntax::ast;
+use syntax::{ast, ast_util};
 use syntax::codemap::span;
 use syntax::print::pprust::{lifetime_to_str, path_to_str};
 use syntax::parse::token::special_idents;
@@ -400,12 +400,13 @@ pub fn ast_ty_to_ty<AC:AstConv, RS:region_scope + Copy + Durable>(
             check_path_args(tcx, path, NO_TPS | NO_REGIONS);
             ty::mk_param(tcx, n, id)
           }
-          ast::def_self_ty(_) => {
+          ast::def_self_ty(id) => {
             // n.b.: resolve guarantees that the self type only appears in a
             // trait, which we rely upon in various places when creating
             // substs
             check_path_args(tcx, path, NO_TPS | NO_REGIONS);
-            ty::mk_self(tcx)
+            let did = ast_util::local_def(id);
+            ty::mk_self(tcx, did)
           }
           _ => {
             tcx.sess.span_fatal(ast_ty.span,
diff --git a/src/librustc/middle/typeck/check/method.rs b/src/librustc/middle/typeck/check/method.rs
index 63a210f84eb..cb626dc85e0 100644
--- a/src/librustc/middle/typeck/check/method.rs
+++ b/src/librustc/middle/typeck/check/method.rs
@@ -307,12 +307,9 @@ pub impl LookupContext/&self {
                         self_ty, did, substs, store);
                     self.push_inherent_impl_candidates_for_type(did);
                 }
-                ty_self => {
+                ty_self(self_did) => {
                     // Call is of the form "self.foo()" and appears in one
                     // of a trait's default method implementations.
-                    let self_did = self.fcx.self_info.expect(
-                        ~"self_impl_def_id is undefined (`self` may not \
-                          be in scope here").def_id;
                     let substs = substs {
                         self_r: None,
                         self_ty: None,
@@ -932,7 +929,7 @@ pub impl LookupContext/&self {
             ty_bare_fn(*) | ty_box(*) | ty_uniq(*) | ty_rptr(*) |
             ty_infer(IntVar(_)) |
             ty_infer(FloatVar(_)) |
-            ty_self | ty_param(*) | ty_nil | ty_bot | ty_bool |
+            ty_self(_) | ty_param(*) | ty_nil | ty_bot | ty_bool |
             ty_int(*) | ty_uint(*) |
             ty_float(*) | ty_enum(*) | ty_ptr(*) | ty_struct(*) | ty_tup(*) |
             ty_estr(*) | ty_evec(*) | ty_trait(*) | ty_closure(*) => {
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index 2d35fc17ede..d79e71a926e 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -183,9 +183,6 @@ pub struct FnCtxt {
     // with any nested functions that capture the environment
     // (and with any functions whose environment is being captured).
 
-    // Refers to whichever `self` is in scope, even this FnCtxt is
-    // for a nested closure that captures `self`
-    self_info: Option<SelfInfo>,
     ret_ty: ty::t,
     // Used by loop bodies that return from the outer function
     indirect_ret_ty: Option<ty::t>,
@@ -236,7 +233,6 @@ pub fn blank_fn_ctxt(ccx: @mut CrateCtxt,
 // It's kind of a kludge to manufacture a fake function context
 // and statement context, but we might as well do write the code only once
     @mut FnCtxt {
-        self_info: None,
         ret_ty: rty,
         indirect_ret_ty: None,
         purity: ast::pure_fn,
@@ -332,7 +328,6 @@ pub fn check_fn(ccx: @mut CrateCtxt,
         };
 
         @mut FnCtxt {
-            self_info: self_info,
             ret_ty: ret_ty,
             indirect_ret_ty: indirect_ret_ty,
             purity: purity,
@@ -605,7 +600,8 @@ pub fn check_item(ccx: @mut CrateCtxt, it: @ast::item) {
                 // bodies to check.
               }
               provided(m) => {
-                check_method(ccx, m, ty::mk_self(ccx.tcx), local_def(it.id));
+                let self_ty = ty::mk_self(ccx.tcx, local_def(it.id));
+                check_method(ccx, m, self_ty, local_def(it.id));
               }
             }
         }
@@ -1699,9 +1695,7 @@ pub fn check_expr_with_unifier(fcx: @mut FnCtxt,
             ty::determine_inherited_purity(copy fcx.purity, purity,
                                            fn_ty.sigil);
 
-        // We inherit the same self info as the enclosing scope,
-        // since the function we're checking might capture `self`
-        check_fn(fcx.ccx, fcx.self_info, inherited_purity,
+        check_fn(fcx.ccx, None, inherited_purity,
                  &fn_ty.sig, decl, body, fn_kind,
                  fcx.in_scope_regions, fcx.inh);
     }
diff --git a/src/librustc/middle/typeck/check/regionmanip.rs b/src/librustc/middle/typeck/check/regionmanip.rs
index ffdd40c6cd8..a76a7f08f0e 100644
--- a/src/librustc/middle/typeck/check/regionmanip.rs
+++ b/src/librustc/middle/typeck/check/regionmanip.rs
@@ -48,7 +48,7 @@ pub fn replace_bound_regions_in_fn_sig(
                 _}, _}) => {
         let region = ty::re_bound(ty::br_self);
         let ty = ty::mk_rptr(tcx, region,
-                             ty::mt { ty: ty::mk_self(tcx), mutbl: m });
+                             ty::mt { ty: ty::mk_nil(tcx), mutbl: m });
         all_tys.push(ty);
       }
       _ => {}
diff --git a/src/librustc/middle/typeck/coherence.rs b/src/librustc/middle/typeck/coherence.rs
index 620d64fd58e..d4bf95bb8bb 100644
--- a/src/librustc/middle/typeck/coherence.rs
+++ b/src/librustc/middle/typeck/coherence.rs
@@ -94,7 +94,7 @@ pub fn get_base_type(inference_context: @mut InferCtxt,
 
         ty_nil | ty_bot | ty_bool | ty_int(*) | ty_uint(*) | ty_float(*) |
         ty_estr(*) | ty_evec(*) | ty_bare_fn(*) | ty_closure(*) | ty_tup(*) |
-        ty_infer(*) | ty_param(*) | ty_self | ty_type | ty_opaque_box |
+        ty_infer(*) | ty_param(*) | ty_self(*) | ty_type | ty_opaque_box |
         ty_opaque_closure_ptr(*) | ty_unboxed_vec(*) | ty_err | ty_box(_) |
         ty_uniq(_) | ty_ptr(_) | ty_rptr(_, _) => {
             debug!("(getting base type) no base type; found %?",
diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index d8636470555..c332d3ac674 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -443,7 +443,7 @@ pub fn ty_to_str(cx: ctxt, typ: t) -> ~str {
                    str::from_bytes(~[('a' as u8) + (id as u8)]))
           }
       }
-      ty_self => ~"self",
+      ty_self(*) => ~"self",
       ty_enum(did, ref substs) | ty_struct(did, ref substs) => {
         let path = ty::item_path(cx, did);
         let base = ast_map::path_to_str(path, cx.sess.intr());
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index a2d82bb8ccd..22ec88cd456 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -185,7 +185,7 @@ pub enum def {
                       /* trait */  Option<def_id>,
                       purity),
     def_self(node_id, bool /* is_implicit */),
-    def_self_ty(node_id),
+    def_self_ty(/* trait id */ node_id),
     def_mod(def_id),
     def_foreign_mod(def_id),
     def_const(def_id),