diff --git a/src/client.js b/src/client.js
index 8d9c8f404..f79b38bb2 100644
--- a/src/client.js
+++ b/src/client.js
@@ -52,7 +52,6 @@ import { isCryptoAvailable } from './crypto';
 import { encodeRecoveryKey, decodeRecoveryKey } from './crypto/recoverykey';
 import { keyForNewBackup, keyForExistingBackup } from './crypto/backup_password';
 import { randomString } from './randomstring';
-import { pkSign } from './crypto/PkSigning';
 
 import IndexedDBCryptoStore from './crypto/store/indexeddb-crypto-store';
 
diff --git a/src/crypto/PkSigning.js b/src/crypto/PkSigning.js
deleted file mode 100644
index 357039357..000000000
--- a/src/crypto/PkSigning.js
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
-Copyright 2019 New Vector Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-const anotherjson = require('another-json');
-
-/**
- * Higher level wrapper around olm.PkSigning that signs JSON objects
- * @param {Object} obj Object to sign
- * @param {Uint8Array} seed The private key seed (32 bytes)
- * @param {string} userId The user ID who owns the signing key
- */
-export function pkSign(obj, seed, userId) {
-    const signing = new global.Olm.PkSigning();
-    try {
-        const pubkey = signing.init_with_seed(seed);
-        const sigs = obj.signatures || {};
-        const mysigs = sigs[userId] || {};
-        sigs[userId] = mysigs;
-
-        delete obj.signatures;
-        const unsigned = obj.unsigned;
-        if (obj.unsigned) delete obj.unsigned;
-
-        mysigs['ed25519:' + pubkey] = signing.sign(anotherjson.stringify(obj));
-        obj.signatures = sigs;
-        if (unsigned) obj.unsigned = unsigned;
-    } finally {
-        signing.free();
-    }
-}
diff --git a/src/crypto/index.js b/src/crypto/index.js
index 418034cbd..6456464d3 100644
--- a/src/crypto/index.js
+++ b/src/crypto/index.js
@@ -50,8 +50,6 @@ import {
     newUnknownMethodError,
 } from './verification/Error';
 
-import { pkSign } from './PkSigning';
-
 const defaultVerificationMethods = {
     [ScanQRCode.NAME]: ScanQRCode,
     [ShowQRCode.NAME]: ShowQRCode,