diff --git a/eth2/types/src/deposit.rs b/eth2/types/src/deposit.rs
index 5eb565c2b..bd3355a3f 100644
--- a/eth2/types/src/deposit.rs
+++ b/eth2/types/src/deposit.rs
@@ -1,4 +1,4 @@
-use super::{DepositData, Hash256};
+use super::{DepositData, Hash256, TreeHashVector};
 use crate::test_utils::TestRandom;
 use rand::RngCore;
 use serde_derive::{Deserialize, Serialize};
@@ -11,7 +11,7 @@ use tree_hash_derive::TreeHash;
 /// Spec v0.5.0
 #[derive(Debug, PartialEq, Clone, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom)]
 pub struct Deposit {
-    pub proof: Vec<Hash256>,
+    pub proof: TreeHashVector<Hash256>,
     pub index: u64,
     pub deposit_data: DepositData,
 }
diff --git a/eth2/types/src/test_utils/testing_deposit_builder.rs b/eth2/types/src/test_utils/testing_deposit_builder.rs
index 326858c31..080ed5cfb 100644
--- a/eth2/types/src/test_utils/testing_deposit_builder.rs
+++ b/eth2/types/src/test_utils/testing_deposit_builder.rs
@@ -12,7 +12,7 @@ impl TestingDepositBuilder {
     /// Instantiates a new builder.
     pub fn new(pubkey: PublicKey, amount: u64) -> Self {
         let deposit = Deposit {
-            proof: vec![],
+            proof: vec![].into(),
             index: 0,
             deposit_data: DepositData {
                 amount,