diff --git a/openpgp.d.ts b/openpgp.d.ts
index 3baca2221..b85a652e1 100644
--- a/openpgp.d.ts
+++ b/openpgp.d.ts
@@ -924,6 +924,13 @@ export namespace enums {
   }
 }
 
+export declare class Argon2S2K {
+  constructor(config: Config);
+  salt: Uint8Array;
+  /** @throws Argon2OutOfMemoryError */
+  produceKey(passphrase: string, keySize: number): Promise<Uint8Array>;
+}
+
 interface KDFParamsData {
   version: number;
   hash: enums.hash;
diff --git a/src/index.js b/src/index.js
index 6d9f5cb71..47b46e050 100644
--- a/src/index.js
+++ b/src/index.js
@@ -22,6 +22,7 @@ export { CleartextMessage, readCleartextMessage, createCleartextMessage } from '
 export * from './packet';
 
 export { default as KDFParams } from './type/kdf_params';
+export { default as Argon2S2K, Argon2OutOfMemoryError } from './type/s2k/argon2';
 
 export * from './encoding/armor';