diff --git a/benches/trie.rs b/benches/trie.rs
index c12a8f752..65df58309 100644
--- a/benches/trie.rs
+++ b/benches/trie.rs
@@ -54,7 +54,8 @@ fn trie_insertions_six_high(b: &mut Bencher) {
 
 	b.iter(||{
 		let mut memdb = MemoryDB::new();
-		let mut t = TrieDB::new(&mut memdb);
+		let mut root = H256::new();
+		let mut t = TrieDB::new(&mut memdb, &mut root);
 		for i in d.iter() {
 			t.insert(&i.0, &i.1);
 		}
@@ -88,7 +89,8 @@ fn trie_insertions_six_mid(b: &mut Bencher) {
 	}
 	b.iter(||{
 		let mut memdb = MemoryDB::new();
-		let mut t = TrieDB::new(&mut memdb);
+		let mut root = H256::new();
+		let mut t = TrieDB::new(&mut memdb, &mut root);
 		for i in d.iter() {
 			t.insert(&i.0, &i.1);
 		}
@@ -124,7 +126,8 @@ fn trie_insertions_random_mid(b: &mut Bencher) {
 
 	b.iter(||{
 		let mut memdb = MemoryDB::new();
-		let mut t = TrieDB::new(&mut memdb);
+		let mut root = H256::new();
+		let mut t = TrieDB::new(&mut memdb, &mut root);
 		for i in d.iter() {
 			t.insert(&i.0, &i.1);
 		}
@@ -160,7 +163,8 @@ fn trie_insertions_six_low(b: &mut Bencher) {
 
 	b.iter(||{
 		let mut memdb = MemoryDB::new();
-		let mut t = TrieDB::new(&mut memdb);
+		let mut root = H256::new();
+		let mut t = TrieDB::new(&mut memdb, &mut root);
 		for i in d.iter() {
 			t.insert(&i.0, &i.1);
 		}