diff --git a/src/rlp.rs b/src/rlp.rs
index 81355fb5d..c3f237092 100644
--- a/src/rlp.rs
+++ b/src/rlp.rs
@@ -227,6 +227,10 @@ impl<'a> Rlp<'a> {
 		From::from(self.rlp.at(index).unwrap())
 	}
 
+	pub fn data_at(&self, _index: usize) -> &[u8] {
+		unimplemented!();
+	}
+
 	/// No value
 	/// 
 	/// ```rust