diff --git a/src/helpers/utils.ts b/src/helpers/utils.ts
index 7bd61e5..7430d7d 100644
--- a/src/helpers/utils.ts
+++ b/src/helpers/utils.ts
@@ -7,12 +7,12 @@ import {PUBLIC_KEY_LENGTH, SIGNATURE_LENGTH} from "../constants";
  * @param source
  * @param length
  */
-export function padLeft(source: Buffer, length: number): Buffer {
+export function padLeft(source: Uint8Array, length: number): Buffer {
   assert(source.length <= length, "Given array must be smaller or equal to desired array size");
   const result = Buffer.alloc(length, 0);
-  source.copy(result, length - source.length);
+  result.set(source, length - source.length);
   return result;
 }
 
 export const EMPTY_PUBLIC_KEY = Buffer.alloc(PUBLIC_KEY_LENGTH);
-export const EMPTY_SIGNATURE = Buffer.alloc(SIGNATURE_LENGTH);
\ No newline at end of file
+export const EMPTY_SIGNATURE = Buffer.alloc(SIGNATURE_LENGTH);
diff --git a/src/index.ts b/src/index.ts
index fcab0dd..97840ed 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -2,7 +2,7 @@ import {Keypair} from "./keypair";
 import {PrivateKey} from "./privateKey";
 import {PublicKey} from "./publicKey";
 import {Signature} from "./signature";
-import {BLSPubkey, BLSSecretKey, BLSSignature, Domain, bytes32} from "@chainsafe/eth2.0-types";
+import {BLSPubkey, BLSSecretKey, BLSSignature, Bytes32, Domain} from "@chainsafe/eth2.0-types";
 import {PUBLIC_KEY_LENGTH} from "./constants";
 import assert from "assert";
 
@@ -33,7 +33,7 @@ export function generatePublicKey(secretKey: BLSSecretKey): BLSPubkey {
  * @param messageHash
  * @param domain
  */
-export function sign(secretKey: BLSSecretKey, messageHash: bytes32, domain: Domain): BLSSignature {
+export function sign(secretKey: BLSSecretKey, messageHash: Bytes32, domain: Domain): BLSSignature {
   assert(secretKey, "secretKey is null or undefined");
   assert(messageHash, "messageHash is null or undefined");
   assert(domain, "domain is null or undefined");
@@ -80,7 +80,7 @@ export function aggregatePubkeys(publicKeys: BLSPubkey[]): BLSPubkey {
  * @param signature
  * @param domain
  */
-export function verify(publicKey: BLSPubkey, messageHash: bytes32, signature: BLSSignature, domain: Domain): boolean {
+export function verify(publicKey: BLSPubkey, messageHash: Bytes32, signature: BLSSignature, domain: Domain): boolean {
   assert(publicKey, "publicKey is null or undefined");
   assert(messageHash, "messageHash is null or undefined");
   assert(signature, "signature is null or undefined");
@@ -103,7 +103,7 @@ export function verify(publicKey: BLSPubkey, messageHash: bytes32, signature: BL
  */
 export function verifyMultiple(
   publicKeys: BLSPubkey[],
-  messageHashes: bytes32[],
+  messageHashes: Bytes32[],
   signature: BLSSignature,
   domain: Domain
 ): boolean {
diff --git a/src/privateKey.ts b/src/privateKey.ts
index 03367d9..065d096 100644
--- a/src/privateKey.ts
+++ b/src/privateKey.ts
@@ -1,6 +1,6 @@
 import {SECRET_KEY_LENGTH} from "./constants";
 import assert from "assert";
-import {BLSSecretKey, Domain, bytes32} from "@chainsafe/eth2.0-types";
+import {BLSSecretKey, Bytes32, Domain} from "@chainsafe/eth2.0-types";
 import {SecretKeyType} from "@chainsafe/eth2-bls-wasm";
 import {generateRandomSecretKey} from "@chainsafe/bls-keygen";
 import {getContext} from "./context";
@@ -51,7 +51,7 @@ export class PrivateKey {
   //   return Signature.fromValue(this.value.sign(message));
   // }
 
-  public signMessage(message: bytes32, domain: Domain): Signature {
+  public signMessage(message: Bytes32, domain: Domain): Signature {
     domain = padLeft(domain, 8);
     return Signature.fromValue(this.value.signHashWithDomain(Buffer.concat([message, domain])));
   }
diff --git a/src/publicKey.ts b/src/publicKey.ts
index c74a415..9023339 100644
--- a/src/publicKey.ts
+++ b/src/publicKey.ts
@@ -1,5 +1,5 @@
 import {PrivateKey} from "./privateKey";
-import {BLSPubkey, Domain, bytes32} from "@chainsafe/eth2.0-types";
+import {BLSPubkey, Bytes32, Domain} from "@chainsafe/eth2.0-types";
 import {PublicKeyType} from "@chainsafe/eth2-bls-wasm";
 import {getContext} from "./context";
 import {PUBLIC_KEY_LENGTH} from "./constants";
@@ -22,7 +22,7 @@ export class PublicKey {
   public static fromBytes(bytes: BLSPubkey): PublicKey {
     const context = getContext();
     const publicKey = new context.PublicKey();
-    if(!bytes.equals(EMPTY_PUBLIC_KEY)) {
+    if(!EMPTY_PUBLIC_KEY.equals(bytes)) {
       publicKey.deserialize(bytes);
     }
     return new PublicKey(
@@ -49,7 +49,7 @@ export class PublicKey {
     return agg;
   }
 
-  public verifyMessage(signature: Signature, messageHash: bytes32, domain: Domain): boolean {
+  public verifyMessage(signature: Signature, messageHash: Bytes32, domain: Domain): boolean {
     return this.value.verifyHashWithDomain(signature.getValue(), Buffer.concat([messageHash, domain]));
   }
 
@@ -58,7 +58,7 @@ export class PublicKey {
   }
 
   public toHexString(): string {
-    return `0x${this.toBytesCompressed().toString("hex")}`;
+    return `0x${Buffer.from(this.toBytesCompressed()).toString("hex")}`;
   }
 
   public getValue(): PublicKeyType {
diff --git a/src/signature.ts b/src/signature.ts
index 399da02..3e028bc 100644
--- a/src/signature.ts
+++ b/src/signature.ts
@@ -1,6 +1,6 @@
 import assert from "assert";
 import {FP_POINT_LENGTH} from "./constants";
-import {BLSSignature, Domain, bytes32} from "@chainsafe/eth2.0-types";
+import {BLSSignature, Bytes32, Domain} from "@chainsafe/eth2.0-types";
 import {SignatureType} from "@chainsafe/eth2-bls-wasm";
 import {getContext} from "./context";
 import {PublicKey} from "./publicKey";
@@ -21,7 +21,7 @@ export class Signature {
     );
     const context = getContext();
     const signature = new context.Signature();
-    if(!value.equals(EMPTY_SIGNATURE)) {
+    if(!EMPTY_SIGNATURE.equals(value)) {
       signature.deserialize(value);
     }
     return new Signature(signature);
@@ -43,12 +43,12 @@ export class Signature {
     return this.value;
   }
 
-  public verify(publicKey: PublicKey, message: bytes32, domain: Domain): boolean {
+  public verify(publicKey: PublicKey, message: Bytes32, domain: Domain): boolean {
     domain = padLeft(domain, 8);
     return publicKey.verifyMessage(this, message, domain);
   }
 
-  public verifyMultiple(publicKeys: PublicKey[], messages: bytes32[], domain: Domain): boolean {
+  public verifyMultiple(publicKeys: PublicKey[], messages: Bytes32[], domain: Domain): boolean {
     domain = padLeft(domain, 8);
     return this.value.verifyAggregatedHashWithDomain(
       publicKeys.map((key) => key.getValue()),