diff --git a/index.js b/index.js
index 12f29e39..35c87de4 100644
--- a/index.js
+++ b/index.js
@@ -1,6 +1,4 @@
 const { EventEmitter } = require('events');
-const { Buffer } = require('buffer');
-const bip39 = require('@metamask/bip39');
 const ObservableStore = require('obs-store');
 const encryptor = require('@metamask/browser-passworder');
 const { normalize: normalizeAddress } = require('@metamask/eth-sig-util');
@@ -107,40 +105,23 @@ class KeyringController extends EventEmitter {
    *
    * @fires KeyringController#unlock
    * @param {string} password - The password to encrypt the vault with.
-   * @param {string|Array<number>} seedPhrase - The BIP39-compliant seed phrase,
-   * either as a string or an array of UTF-8 bytes that represent the string.
+   * @param {Uint8Array | string} seedPhrase - The BIP39-compliant seed phrase,
+   * either as a string or Uint8Array.
    * @returns {Promise<object>} A Promise that resolves to the state.
    */
   async createNewVaultAndRestore(password, seedPhrase) {
-    const seedPhraseAsBuffer =
-      typeof seedPhrase === 'string'
-        ? Buffer.from(seedPhrase, 'utf8')
-        : Buffer.from(seedPhrase);
-
     if (typeof password !== 'string') {
       throw new Error('Password must be text.');
     }
-
-    const wordlists = Object.values(bip39.wordlists);
-    if (
-      wordlists.every(
-        (wordlist) => !bip39.validateMnemonic(seedPhraseAsBuffer, wordlist),
-      )
-    ) {
-      throw new Error('Seed phrase is invalid.');
-    }
-
     this.password = password;
 
-    this.clearKeyrings();
-    const firstKeyring = await this.addNewKeyring(
-      KEYRINGS_TYPE_MAP.HD_KEYRING,
-      {
-        mnemonic: seedPhraseAsBuffer,
-        numberOfAccounts: 1,
-      },
-    );
-    const [firstAccount] = await firstKeyring.getAccounts();
+    await this.clearKeyrings();
+    const keyring = await this.addNewKeyring(KEYRINGS_TYPE_MAP.HD_KEYRING, {
+      mnemonic: seedPhrase,
+      numberOfAccounts: 1,
+    });
+    const [firstAccount] = await keyring.getAccounts();
+
     if (!firstAccount) {
       throw new Error('KeyringController - First Account not found.');
     }
diff --git a/package.json b/package.json
index cafec1c5..b03ef9bd 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,6 @@
     "lint:fix": "yarn lint:eslint --fix && yarn lint:misc --write"
   },
   "dependencies": {
-    "@metamask/bip39": "^4.0.0",
     "@metamask/browser-passworder": "^4.0.1",
     "@metamask/eth-hd-keyring": "^5.0.1",
     "@metamask/eth-sig-util": "5.0.2",
diff --git a/test/index.js b/test/index.js
index 4fdb7e37..30e8c3f4 100644
--- a/test/index.js
+++ b/test/index.js
@@ -189,7 +189,15 @@ describe('KeyringController', function () {
           password,
           'test test test palace city barely security section midnight wealth south deer',
         ),
-      ).rejects.toThrow('Seed phrase is invalid.');
+      ).rejects.toThrow(
+        'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
+      );
+
+      await expect(() =>
+        keyringController.createNewVaultAndRestore(password, 1234),
+      ).rejects.toThrow(
+        'Eth-Hd-Keyring: Invalid secret recovery phrase provided',
+      );
     });
 
     it('accepts mnemonic passed as type array of numbers', async function () {
diff --git a/yarn.lock b/yarn.lock
index a466c7fe..a99eb022 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -758,18 +758,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@metamask/bip39@npm:^4.0.0":
-  version: 4.0.0
-  resolution: "@metamask/bip39@npm:4.0.0"
-  dependencies:
-    "@types/node": 11.11.6
-    create-hash: ^1.1.0
-    pbkdf2: ^3.0.9
-    randombytes: ^2.0.1
-  checksum: 0d629de806dd0a6c6ea2ff4ab4752931b15eda5abcf2975f3beed8b4161bcc4765ec97bd8ba0146059b10178f6cf1753f74223655908bc585a76b565f26d4f16
-  languageName: node
-  linkType: hard
-
 "@metamask/browser-passworder@npm:^4.0.1":
   version: 4.0.2
   resolution: "@metamask/browser-passworder@npm:4.0.2"
@@ -1158,13 +1146,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/node@npm:11.11.6":
-  version: 11.11.6
-  resolution: "@types/node@npm:11.11.6"
-  checksum: 075f1c011cf568e49701419acbcb55c24906b3bb5a34d9412a3b88f228a7a78401a5ad4d3e1cd6855c99aaea5ef96e37fc86ca097e50f06da92cf822befc1fff
-  languageName: node
-  linkType: hard
-
 "@types/pbkdf2@npm:^3.0.0":
   version: 3.1.0
   resolution: "@types/pbkdf2@npm:3.1.0"
@@ -2786,7 +2767,6 @@ __metadata:
   dependencies:
     "@lavamoat/allow-scripts": ^2.1.0
     "@metamask/auto-changelog": ^3.0.0
-    "@metamask/bip39": ^4.0.0
     "@metamask/browser-passworder": ^4.0.1
     "@metamask/eslint-config": ^10.0.0
     "@metamask/eslint-config-jest": ^10.0.0
@@ -5383,7 +5363,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"pbkdf2@npm:^3.0.17, pbkdf2@npm:^3.0.9":
+"pbkdf2@npm:^3.0.17":
   version: 3.1.1
   resolution: "pbkdf2@npm:3.1.1"
   dependencies:
@@ -5545,7 +5525,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"randombytes@npm:^2.0.1, randombytes@npm:^2.0.6, randombytes@npm:^2.1.0":
+"randombytes@npm:^2.0.6, randombytes@npm:^2.1.0":
   version: 2.1.0
   resolution: "randombytes@npm:2.1.0"
   dependencies: