diff --git a/packages/wallets/wallet-private-key/src/strategy/strategy.ts b/packages/wallets/wallet-private-key/src/strategy/strategy.ts
index 993ce9210..bf1b5b79c 100644
--- a/packages/wallets/wallet-private-key/src/strategy/strategy.ts
+++ b/packages/wallets/wallet-private-key/src/strategy/strategy.ts
@@ -204,7 +204,7 @@ export class PrivateKeyWallet
     try {
       const signature = await pk.signHashed(Buffer.from(toUtf8(data), 'utf-8'))
 
-      return signature
+      return `0x${Buffer.from(signature).toString('base64')}`
     } catch (e: unknown) {
       throw new MetamaskException(new Error((e as any).message), {
         code: UnspecifiedErrorCode,