diff --git a/src/libcore/to_bytes.rs b/src/libcore/to_bytes.rs
index 7b4b6994e50..e563a304f09 100644
--- a/src/libcore/to_bytes.rs
+++ b/src/libcore/to_bytes.rs
@@ -419,8 +419,7 @@ fn iter_bytes(&self, lsb0: bool, f: Cb) {
     }
 }
 
-
-trait ToBytes {
+pub trait ToBytes {
     fn to_bytes(&self, lsb0: bool) -> ~[u8];
 }