diff --git a/src/handshake.ts b/src/handshake.ts
index e794b1e..1592591 100644
--- a/src/handshake.ts
+++ b/src/handshake.ts
@@ -4,7 +4,7 @@ import { equals as uint8ArrayEquals } from "uint8arrays/equals";
 
 import { bytes32 } from "./@types/basic";
 import { KeyPair } from "./@types/keypair";
-import { HKDF } from "./crypto";
+import { HKDF } from "./crypto.js";
 import { HandshakeState, NoisePaddingBlockSize } from "./handshake_state.js";
 import { MessageNametagBuffer, toMessageNametag } from "./messagenametag";
 import { CipherState } from "./noise.js";
diff --git a/src/handshake_state.ts b/src/handshake_state.ts
index f3aecdb..87ad487 100644
--- a/src/handshake_state.ts
+++ b/src/handshake_state.ts
@@ -6,7 +6,7 @@ import { bytes32 } from "./@types/basic.js";
 import { MessageNametag } from "./@types/handshake.js";
 import type { KeyPair } from "./@types/keypair.js";
 import { Curve25519KeySize, dh, generateX25519KeyPair, HKDF, intoCurve25519Key } from "./crypto.js";
-import { MessageNametagLength } from "./messagenametag";
+import { MessageNametagLength } from "./messagenametag.js";
 import { SymmetricState } from "./noise.js";
 import { HandshakePattern, MessageDirection, NoiseTokens, PreMessagePattern } from "./patterns.js";
 import { NoisePublicKey } from "./publickey.js";