diff --git a/src/test/bench/core-std.rs b/src/test/bench/core-std.rs
index e8fb86fda78..eecf509998b 100644
--- a/src/test/bench/core-std.rs
+++ b/src/test/bench/core-std.rs
@@ -17,6 +17,7 @@
 use std::oldmap::{Map, HashMap};
 
 use core::io::{Reader, ReaderUtil};
+use core::rand::RngUtil;
 
 macro_rules! bench (
     ($id:ident) => (maybe_run_test(argv, stringify!($id).to_owned(), $id))
diff --git a/src/test/bench/graph500-bfs.rs b/src/test/bench/graph500-bfs.rs
index 8da09af2d18..b99dfa8bacb 100644
--- a/src/test/bench/graph500-bfs.rs
+++ b/src/test/bench/graph500-bfs.rs
@@ -29,6 +29,7 @@
 use std::par;
 use core::io::WriterUtil;
 use core::int::abs;
+use core::rand::RngUtil;
 
 type node_id = i64;
 type graph = ~[~[node_id]];
@@ -37,7 +38,7 @@
 fn make_edges(scale: uint, edgefactor: uint) -> ~[(node_id, node_id)] {
     let r = rand::xorshift();
 
-    fn choose_edge(i: node_id, j: node_id, scale: uint, r: rand::Rng)
+    fn choose_edge(i: node_id, j: node_id, scale: uint, r: @rand::Rng)
         -> (node_id, node_id) {
 
         let A = 0.57;
diff --git a/src/test/bench/noise.rs b/src/test/bench/noise.rs
index 9825671bc8a..7993822afd8 100644
--- a/src/test/bench/noise.rs
+++ b/src/test/bench/noise.rs
@@ -1,5 +1,7 @@
 // Perlin noise benchmark from https://gist.github.com/1170424
 
+use core::rand::RngUtil;
+
 struct Vec2 {
     x: f32,
     y: f32,
@@ -8,7 +10,7 @@ struct Vec2 {
 fn lerp(a: f32, b: f32, v: f32) -> f32  { a * (1.0 - v) + b * v }
 fn smooth(v: f32) -> f32                { v * v * (3.0 - 2.0 * v) }
 
-fn random_gradient(r: rand::Rng) -> Vec2 {
+fn random_gradient(r: @rand::Rng) -> Vec2 {
     let v = r.gen_float() * float::consts::pi * 2.0;
     Vec2{
         x: float::cos(v) as f32,
diff --git a/src/test/bench/shootout-fasta.rs b/src/test/bench/shootout-fasta.rs
index 2bc89f64a29..8c371150e1e 100644
--- a/src/test/bench/shootout-fasta.rs
+++ b/src/test/bench/shootout-fasta.rs
@@ -57,7 +57,11 @@ fn bisect(v: ~[AminoAcids], lo: uint, hi: uint, target: u32) -> char {
     return bisect(copy genelist, 0, vec::len::<AminoAcids>(genelist) - 1, r);
 }
 
-fn make_random_fasta(wr: io::Writer, id: ~str, desc: ~str, genelist: ~[AminoAcids], n: int) {
+fn make_random_fasta(wr: @io::Writer,
+                     id: ~str,
+                     desc: ~str,
+                     genelist: ~[AminoAcids],
+                     n: int) {
     wr.write_line(~">" + id + ~" " + desc);
     let rng = @mut MyRandom {last: rand::Rng().next()};
     let mut op: ~str = ~"";
@@ -72,7 +76,7 @@ fn make_random_fasta(wr: io::Writer, id: ~str, desc: ~str, genelist: ~[AminoAcid
     if str::len(op) > 0u { wr.write_line(op); }
 }
 
-fn make_repeat_fasta(wr: io::Writer, id: ~str, desc: ~str, s: ~str, n: int) {
+fn make_repeat_fasta(wr: @io::Writer, id: ~str, desc: ~str, s: ~str, n: int) {
     unsafe {
         wr.write_line(~">" + id + ~" " + desc);
         let mut op: ~str = ~"";
diff --git a/src/test/bench/shootout-mandelbrot.rs b/src/test/bench/shootout-mandelbrot.rs
index 146a4b8c869..eeea62d50fb 100644
--- a/src/test/bench/shootout-mandelbrot.rs
+++ b/src/test/bench/shootout-mandelbrot.rs
@@ -110,7 +110,7 @@ fn get_type(&self) -> io::WriterType { io::File }
 
 fn writer(path: ~str, pport: comm::Port<Line>, size: uint)
 {
-    let cout: io::Writer = match path {
+    let cout: @io::Writer = match path {
         ~"" => {
             @Devnull as @io::Writer
         }
diff --git a/src/test/bench/sudoku.rs b/src/test/bench/sudoku.rs
index 78234ca0dfa..e2edb1a94ea 100644
--- a/src/test/bench/sudoku.rs
+++ b/src/test/bench/sudoku.rs
@@ -39,7 +39,7 @@
 pub enum grid_t { grid_ctor(grid), }
 
 // read a sudoku problem from file f
-pub fn read_grid(f: io::Reader) -> grid_t {
+pub fn read_grid(f: @io::Reader) -> grid_t {
     fail_unless!(f.read_line() == ~"9,9"); /* assert first line is exactly "9,9" */
 
     let mut g = vec::from_fn(10u, {|_i|
@@ -127,7 +127,7 @@ fn drop_color(g: grid, mut colors: bitv::Bitv, row: u8, col: u8) {
     }
 }
 
-pub fn write_grid(f: io::Writer, g: grid_t) {
+pub fn write_grid(f: @io::Writer, g: grid_t) {
     for u8::range(0u8, 9u8) |row| {
         f.write_str(fmt!("%u", (*g)[row][0] as uint));
         for u8::range(1u8, 9u8) |col| {