diff --git a/sync/src/tests/helpers.rs b/sync/src/tests/helpers.rs
index a5a60d62d..ee052ed5a 100644
--- a/sync/src/tests/helpers.rs
+++ b/sync/src/tests/helpers.rs
@@ -76,6 +76,10 @@ impl BlockChainClient for TestBlockChainClient {
 		unimplemented!();
 	}
 
+	fn code(&self, _address: &Address) -> Option<Bytes> {
+		unimplemented!();
+	}
+
 	fn block_header(&self, h: &H256) -> Option<Bytes> {
 		self.blocks.read().unwrap().get(h).map(|r| Rlp::new(r).at(0).as_raw().to_vec())