diff --git a/src/rlp/rlpstream.rs b/src/rlp/rlpstream.rs
index 301a39053..43ae83a9a 100644
--- a/src/rlp/rlpstream.rs
+++ b/src/rlp/rlpstream.rs
@@ -101,6 +101,10 @@ impl Stream for RlpStream {
 		self.unfinished_lists.len() == 0
 	}
 
+	fn raw(&self) -> &[u8] {
+		&self.encoder.bytes
+	}
+
 	fn out(self) -> Vec<u8> {
 		match self.is_finished() {
 			true => self.encoder.out().to_vec(),
diff --git a/src/rlp/traits.rs b/src/rlp/traits.rs
index 1127ca3db..4f9ad09e5 100644
--- a/src/rlp/traits.rs
+++ b/src/rlp/traits.rs
@@ -282,6 +282,8 @@ pub trait Stream: Sized {
 	/// }
 	fn is_finished(&self) -> bool;
 
+	fn raw(&self) -> &[u8];
+
 	/// Streams out encoded bytes.
 	/// 
 	/// panic! if stream is not finished.