diff --git a/node_modules/eth-hd-keyring/index.js b/node_modules/eth-hd-keyring/index.js
index 19d1d7f..350d6b8 100644
--- a/node_modules/eth-hd-keyring/index.js
+++ b/node_modules/eth-hd-keyring/index.js
@@ -17,8 +17,11 @@ class HdKeyring extends SimpleKeyring {
   }
 
   serialize () {
+    const mnemonicAsBuffer = typeof this.mnemonic === 'string'
+      ? Buffer.from(this.mnemonic, 'utf8')
+      : this.mnemonic
     return Promise.resolve({
-      mnemonic: this.mnemonic,
+      mnemonic: Array.from(mnemonicAsBuffer.values()),
       numberOfAccounts: this.wallets.length,
       hdPath: this.hdPath,
     })
@@ -69,9 +72,22 @@ class HdKeyring extends SimpleKeyring {
 
   /* PRIVATE METHODS */
 
-  _initFromMnemonic (mnemonic) {
-    this.mnemonic = mnemonic
-    const seed = bip39.mnemonicToSeed(mnemonic)
+  /**
+   * Sets appropriate properties for the keyring based on the given
+   * BIP39-compliant mnemonic.
+   *
+   * @param {string|Array<number>|Buffer} mnemonic - A seed phrase represented
+   * as a string, an array of UTF-8 bytes, or a Buffer.
+   */
+  _initFromMnemonic(mnemonic) {
+    if (typeof mnemonic === 'string') {
+      this.mnemonic = Buffer.from(mnemonic, 'utf8')
+    } else if (Array.isArray(mnemonic)) {
+      this.mnemonic = Buffer.from(mnemonic)
+    } else {
+      this.mnemonic = mnemonic
+    }
+    const seed = bip39.mnemonicToSeed(this.mnemonic)
     this.hdWallet = hdkey.fromMasterSeed(seed)
     this.root = this.hdWallet.derivePath(this.hdPath)
   }