diff --git a/src/libstd/fun_treemap.rs b/src/libstd/fun_treemap.rs
index 714d6c93ffa2..778a62eebbe4 100644
--- a/src/libstd/fun_treemap.rs
+++ b/src/libstd/fun_treemap.rs
@@ -60,7 +60,7 @@ fn find<K: Eq Ord, V: Copy>(m: Treemap<K, V>, +k: K) -> Option<V> {
 }
 
 /// Visit all pairs in the map in order.
-fn traverse<K, V: Copy>(m: Treemap<K, V>, f: fn(K, V)) {
+fn traverse<K, V: Copy>(m: Treemap<K, V>, f: fn((&K), (&V))) {
     match *m {
       Empty => (),
       /*
@@ -72,7 +72,7 @@ fn traverse<K, V: Copy>(m: Treemap<K, V>, f: fn(K, V)) {
         // copy v to make aliases work out
         let v1 = v;
         traverse(left, f);
-        f(k, v1);
+        f(&k, &v1);
         traverse(right, f);
       }
     }
diff --git a/src/libstd/list.rs b/src/libstd/list.rs
index b4e8678f6ae4..297720cbde9c 100644
--- a/src/libstd/list.rs
+++ b/src/libstd/list.rs
@@ -32,7 +32,7 @@ fn from_vec<T: Copy>(v: &[T]) -> @List<T> {
  */
 fn foldl<T: Copy, U>(+z: T, ls: @List<U>, f: fn((&T), (&U)) -> T) -> T {
     let mut accum: T = z;
-    do iter(ls) |elt| { accum = f(&accum, &elt);}
+    do iter(ls) |elt| { accum = f(&accum, elt);}
     accum
 }
 
@@ -121,11 +121,11 @@ pure fn push<T: Copy>(ll: &mut @list<T>, +vv: T) {
 */
 
 /// Iterate over a list
-fn iter<T>(l: @List<T>, f: fn(T)) {
+fn iter<T>(l: @List<T>, f: fn((&T))) {
     let mut cur = l;
     loop {
         cur = match *cur {
-          Cons(hd, tl) => {
+          Cons(ref hd, tl) => {
             f(hd);
             tl
           }