diff --git a/src/lib/_str.rs b/src/lib/_str.rs
index f1de80f1d28..167b9f67754 100644
--- a/src/lib/_str.rs
+++ b/src/lib/_str.rs
@@ -5,6 +5,7 @@ native "rust" mod rustrt {
   fn str_buf(str s) -> sbuf;
   fn str_len(str s) -> uint;
   fn str_alloc(uint n_bytes) -> str;
+  fn refcount[T](str s) -> uint;
 }
 
 fn is_utf8(vec[u8] v) -> bool {
diff --git a/src/lib/_vec.rs b/src/lib/_vec.rs
index 3074df2cd25..06e738f5156 100644
--- a/src/lib/_vec.rs
+++ b/src/lib/_vec.rs
@@ -6,6 +6,7 @@ native "rust" mod rustrt {
   fn vec_buf[T](vec[T] v) -> vbuf;
   fn vec_len[T](vec[T] v) -> uint;
   fn vec_alloc[T](uint n_elts) -> vec[T];
+  fn refcount[T](vec[T] v) -> uint;
 }
 
 fn alloc[T](uint n_elts) -> vec[T] {