diff --git a/src/index.ts b/src/index.ts
index 9b55c9a..cad6199 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,4 @@
-import {IBls} from "./interface";
+import {IBls, IPrivateKey, IPublicKey, ISignature} from "./interface";
 import {bls as blsHerumi} from "./herumi";
 
 export type Implementation = "herumi" | "blst-native";
@@ -7,6 +7,7 @@ export * from "./interface";
 
 // TODO: Use a Proxy for example to throw an error if it's not initialized yet
 export const bls: IBls = {} as IBls;
+export default bls;
 
 async function getImplementation(impl: Implementation = "herumi"): Promise<IBls> {
   switch (impl) {
@@ -43,8 +44,32 @@ export declare let aggregatePubkeys: IBls["aggregatePubkeys"];
 export declare let verify: IBls["verify"];
 export declare let verifyAggregate: IBls["verifyAggregate"];
 export declare let verifyMultiple: IBls["verifyMultiple"];
-export declare let PrivateKey: IBls["PrivateKey"];
-export declare let PublicKey: IBls["PublicKey"];
-export declare let Signature: IBls["Signature"];
 
-export default bls;
+export declare class PrivateKey implements IPrivateKey {
+  static fromBytes(bytes: Uint8Array): PrivateKey;
+  static fromHex(hex: string): PrivateKey;
+  static fromKeygen(entropy?: Uint8Array): PrivateKey;
+  sign(message: Uint8Array): Signature;
+  toPublicKey(): PublicKey;
+  toBytes(): Uint8Array;
+  toHex(): string;
+}
+
+export declare class PublicKey implements IPublicKey {
+  static fromBytes(bytes: Uint8Array): PublicKey;
+  static fromHex(hex: string): PublicKey;
+  static aggregate(pubkeys: PublicKey[]): PublicKey;
+  toBytes(): Uint8Array;
+  toHex(): string;
+}
+
+export declare class Signature implements ISignature {
+  static fromBytes(bytes: Uint8Array): Signature;
+  static fromHex(hex: string): Signature;
+  static aggregate(signatures: Signature[]): Signature;
+  verify(publicKey: PublicKey, message: Uint8Array): boolean;
+  verifyAggregate(publicKeys: PublicKey[], message: Uint8Array): boolean;
+  verifyMultiple(publicKeys: PublicKey[], messages: Uint8Array[]): boolean;
+  toBytes(): Uint8Array;
+  toHex(): string;
+}