diff --git a/src/librustc/middle/trans/callee.rs b/src/librustc/middle/trans/callee.rs
index 8ef55f89d81..6d139130e2b 100644
--- a/src/librustc/middle/trans/callee.rs
+++ b/src/librustc/middle/trans/callee.rs
@@ -615,10 +615,7 @@ pub fn trans_call_inner(in_cx: block,
                 }
                 Method(d) => {
                     // Weird but true: we pass self in the *environment* slot!
-                    let llself = PointerCast(bcx,
-                                             d.llself,
-                                             Type::opaque_box(ccx).ptr_to());
-                    (d.llfn, llself)
+                    (d.llfn, d.llself)
                 }
                 Closure(d) => {
                     // Closures are represented as (llfn, llclosure) pair:
@@ -944,10 +941,6 @@ pub fn trans_arg_expr(bcx: block,
         if formal_arg_ty != arg_datum.ty {
             // this could happen due to e.g. subtyping
             let llformal_arg_ty = type_of::type_of_explicit_arg(ccx, &formal_arg_ty);
-            let llformal_arg_ty = match self_mode {
-                ty::ByRef => llformal_arg_ty.ptr_to(),
-                ty::ByCopy => llformal_arg_ty,
-            };
             debug!("casting actual type (%s) to match formal (%s)",
                    bcx.val_to_str(val), bcx.llty_str(llformal_arg_ty));
             val = PointerCast(bcx, val, llformal_arg_ty);
diff --git a/src/librustc/middle/trans/meth.rs b/src/librustc/middle/trans/meth.rs
index 0b051662781..fa32dd5b93e 100644
--- a/src/librustc/middle/trans/meth.rs
+++ b/src/librustc/middle/trans/meth.rs
@@ -133,8 +133,8 @@ pub fn trans_self_arg(bcx: block,
     let _icx = push_ctxt("impl::trans_self_arg");
     let mut temp_cleanups = ~[];
 
-    // Compute the type of self.
-    let self_ty = monomorphize_type(bcx, mentry.self_ty);
+    // self is passed as an opaque box in the environment slot
+    let self_ty = ty::mk_opaque_box(bcx.tcx());
     let result = trans_arg_expr(bcx,
                                 self_ty,
                                 mentry.self_mode,
@@ -576,7 +576,6 @@ pub fn trans_trait_callee_from_llval(bcx: block,
     let llbox = Load(bcx, GEPi(bcx, llpair, [0u, abi::trt_field_box]));
 
     // Munge `llself` appropriately for the type of `self` in the method.
-    let self_mode;
     match explicit_self {
         ast::sty_static => {
             bcx.tcx().sess.bug("shouldn't see static method here");
@@ -597,12 +596,6 @@ pub fn trans_trait_callee_from_llval(bcx: block,
                     llself = llbox;
                 }
             }
-
-            let llscratch = alloca(bcx, val_ty(llself));
-            Store(bcx, llself, llscratch);
-            llself = llscratch;
-
-            self_mode = ty::ByRef;
         }
         ast::sty_box(_) => {
             // Bump the reference count on the box.
@@ -615,12 +608,6 @@ pub fn trans_trait_callee_from_llval(bcx: block,
                 ty::BoxTraitStore => llself = llbox,
                 _ => bcx.tcx().sess.bug("@self receiver with non-@Trait")
             }
-
-            let llscratch = alloca(bcx, val_ty(llself));
-            Store(bcx, llself, llscratch);
-            llself = llscratch;
-
-            self_mode = ty::ByRef;
         }
         ast::sty_uniq(_) => {
             // Pass the unique pointer.
@@ -628,15 +615,13 @@ pub fn trans_trait_callee_from_llval(bcx: block,
                 ty::UniqTraitStore => llself = llbox,
                 _ => bcx.tcx().sess.bug("~self receiver with non-~Trait")
             }
-
-            let llscratch = alloca(bcx, val_ty(llself));
-            Store(bcx, llself, llscratch);
-            llself = llscratch;
-
-            self_mode = ty::ByRef;
         }
     }
 
+    let llscratch = alloca(bcx, val_ty(llself));
+    Store(bcx, llself, llscratch);
+    llself = PointerCast(bcx, llscratch, Type::opaque_box(ccx).ptr_to());
+
     // Load the function from the vtable and cast it to the expected type.
     debug!("(translating trait callee) loading method");
     let llcallee_ty = type_of_fn_from_ty(ccx, callee_ty);
@@ -652,7 +637,7 @@ pub fn trans_trait_callee_from_llval(bcx: block,
             llfn: mptr,
             llself: llself,
             self_ty: ty::mk_opaque_box(bcx.tcx()),
-            self_mode: self_mode,
+            self_mode: ty::ByRef,
             explicit_self: explicit_self
             /* XXX: Some(llbox) */
         })