diff --git a/spec/unit/secret-storage.spec.ts b/spec/unit/secret-storage.spec.ts
index b2346d88e6c..b71da45e2f8 100644
--- a/spec/unit/secret-storage.spec.ts
+++ b/spec/unit/secret-storage.spec.ts
@@ -18,7 +18,6 @@ import { Mocked } from "jest-mock";
 
 import {
     AccountDataClient,
-    calculateKeyCheck,
     PassphraseInfo,
     SecretStorageCallbacks,
     SecretStorageKeyDescriptionAesV1,
@@ -27,6 +26,7 @@ import {
     trimTrailingEquals,
 } from "../../src/secret-storage";
 import { randomString } from "../../src/randomstring";
+import { calculateKeyCheck } from "../../src/calculateKeyCheck.ts";
 
 describe("ServerSideSecretStorageImpl", function () {
     describe(".addKey", function () {
diff --git a/src/calculateKeyCheck.ts b/src/calculateKeyCheck.ts
new file mode 100644
index 00000000000..7e979a71263
--- /dev/null
+++ b/src/calculateKeyCheck.ts
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2024 The Matrix.org Foundation C.I.C.
+ *
+ * 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.
+ */
+
+// string of zeroes, for calculating the key check
+import encryptAESSecretStorageItem from "./utils/encryptAESSecretStorageItem.ts";
+import { AESEncryptedSecretStoragePayload } from "./@types/AESEncryptedSecretStoragePayload.ts";
+
+const ZERO_STR = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+
+/**
+ * Calculate the MAC for checking the key.
+ * See https://spec.matrix.org/v1.11/client-server-api/#msecret_storagev1aes-hmac-sha2, steps 3 and 4.
+ *
+ * @param key - the key to use
+ * @param iv - The initialization vector as a base64-encoded string.
+ *     If omitted, a random initialization vector will be created.
+ * @returns An object that contains, `mac` and `iv` properties.
+ */
+export function calculateKeyCheck(key: Uint8Array, iv?: string): Promise<AESEncryptedSecretStoragePayload> {
+    return encryptAESSecretStorageItem(ZERO_STR, key, "", iv);
+}
diff --git a/src/crypto/aes.ts b/src/crypto/aes.ts
index 7ea79770095..f435d8c15e5 100644
--- a/src/crypto/aes.ts
+++ b/src/crypto/aes.ts
@@ -16,8 +16,11 @@ limitations under the License.
 
 import encryptAESSecretStorageItem from "../utils/encryptAESSecretStorageItem.ts";
 import decryptAESSecretStorageItem from "../utils/decryptAESSecretStorageItem.ts";
+import { AESEncryptedSecretStoragePayload } from "../@types/AESEncryptedSecretStoragePayload.ts";
 
 // Export for backwards compatibility
-export type { AESEncryptedSecretStoragePayload as IEncryptedPayload } from "../@types/AESEncryptedSecretStoragePayload.ts";
-export { encryptAESSecretStorageItem, decryptAESSecretStorageItem };
-export { calculateKeyCheck } from "../secret-storage.ts";
+export type { AESEncryptedSecretStoragePayload as IEncryptedPayload };
+// Export with new names instead of using `as` to not break react-sdk tests
+export const encryptAES = encryptAESSecretStorageItem;
+export const decryptAES = decryptAESSecretStorageItem;
+export { calculateKeyCheck } from "../calculateKeyCheck.ts";
diff --git a/src/crypto/backup.ts b/src/crypto/backup.ts
index 39bcaae6126..7caf069ab4a 100644
--- a/src/crypto/backup.ts
+++ b/src/crypto/backup.ts
@@ -43,7 +43,7 @@ import { encodeRecoveryKey } from "../crypto-api/index.ts";
 import decryptAESSecretStorageItem from "../utils/decryptAESSecretStorageItem.ts";
 import encryptAESSecretStorageItem from "../utils/encryptAESSecretStorageItem.ts";
 import { AESEncryptedSecretStoragePayload } from "../@types/AESEncryptedSecretStoragePayload.ts";
-import { calculateKeyCheck } from "../secret-storage.ts";
+import { calculateKeyCheck } from "../calculateKeyCheck.ts";
 
 const KEY_BACKUP_KEYS_PER_REQUEST = 200;
 const KEY_BACKUP_CHECK_RATE_LIMIT = 5000; // ms
diff --git a/src/crypto/index.ts b/src/crypto/index.ts
index 9f4b3978187..932ce3adf48 100644
--- a/src/crypto/index.ts
+++ b/src/crypto/index.ts
@@ -75,7 +75,6 @@ import { MapWithDefault, recursiveMapToObject } from "../utils.ts";
 import {
     AccountDataClient,
     AddSecretStorageKeyOpts,
-    calculateKeyCheck,
     SECRET_STORAGE_ALGORITHM_V1_AES,
     SecretStorageKeyDescription,
     SecretStorageKeyObject,
@@ -110,6 +109,7 @@ import { KnownMembership } from "../@types/membership.ts";
 import decryptAESSecretStorageItem from "../utils/decryptAESSecretStorageItem.ts";
 import encryptAESSecretStorageItem from "../utils/encryptAESSecretStorageItem.ts";
 import { AESEncryptedSecretStoragePayload } from "../@types/AESEncryptedSecretStoragePayload.ts";
+import { calculateKeyCheck } from "../calculateKeyCheck.ts";
 
 /* re-exports for backwards compatibility */
 export type {
diff --git a/src/secret-storage.ts b/src/secret-storage.ts
index 13e8bdc625b..f192ddfd7f5 100644
--- a/src/secret-storage.ts
+++ b/src/secret-storage.ts
@@ -28,6 +28,7 @@ import { logger } from "./logger.ts";
 import encryptAESSecretStorageItem from "./utils/encryptAESSecretStorageItem.ts";
 import decryptAESSecretStorageItem from "./utils/decryptAESSecretStorageItem.ts";
 import { AESEncryptedSecretStoragePayload } from "./@types/AESEncryptedSecretStoragePayload.ts";
+import { calculateKeyCheck } from "./crypto/aes.ts";
 
 export const SECRET_STORAGE_ALGORITHM_V1_AES = "m.secret_storage.v1.aes-hmac-sha2";
 
@@ -675,19 +676,3 @@ export function trimTrailingEquals(input: string): string {
         return input;
     }
 }
-
-// string of zeroes, for calculating the key check
-const ZERO_STR = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
-
-/**
- * Calculate the MAC for checking the key.
- * See https://spec.matrix.org/v1.11/client-server-api/#msecret_storagev1aes-hmac-sha2, steps 3 and 4.
- *
- * @param key - the key to use
- * @param iv - The initialization vector as a base64-encoded string.
- *     If omitted, a random initialization vector will be created.
- * @returns An object that contains, `mac` and `iv` properties.
- */
-export function calculateKeyCheck(key: Uint8Array, iv?: string): Promise<AESEncryptedSecretStoragePayload> {
-    return encryptAESSecretStorageItem(ZERO_STR, key, "", iv);
-}