diff --git a/core/src/main/kotlin/core/crypto/CryptoUtilities.kt b/core/src/main/kotlin/core/crypto/CryptoUtilities.kt
index 7827f279eb..6453a987f4 100644
--- a/core/src/main/kotlin/core/crypto/CryptoUtilities.kt
+++ b/core/src/main/kotlin/core/crypto/CryptoUtilities.kt
@@ -99,6 +99,7 @@ fun PrivateKey.signWithECDSA(bitsToSign: ByteArray, publicKey: PublicKey): Digit
 }
 fun KeyPair.signWithECDSA(bitsToSign: ByteArray) = private.signWithECDSA(bitsToSign, public)
 fun KeyPair.signWithECDSA(bitsToSign: OpaqueBytes) = private.signWithECDSA(bitsToSign.bits, public)
+fun KeyPair.signWithECDSA(bitsToSign: OpaqueBytes, party: Party) = signWithECDSA(bitsToSign.bits, party)
 fun KeyPair.signWithECDSA(bitsToSign: ByteArray, party: Party): DigitalSignature.LegallyIdentifiable {
     check(public == party.owningKey)
     val sig = signWithECDSA(bitsToSign)