diff --git a/docker-compose.yml b/docker-compose.yml
index eb6136bb..c9d152fb 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -33,7 +33,7 @@ services:
       retries: 3
     command: -l DEBUG start
   tendermint:
-    image: tendermint/tendermint:0.22.3
+    image: tendermint/tendermint:0.22.8
     # volumes:
     #   - ./tmdata:/tendermint
     entrypoint: ''
diff --git a/src/transaction.js b/src/transaction.js
index f28f70ac..88f821ea 100644
--- a/src/transaction.js
+++ b/src/transaction.js
@@ -236,7 +236,7 @@ export default class Transaction {
             Transaction.serializeTransactionIntoCanonicalString(transaction)
 
         signedTx.inputs.forEach((input, index) => {
-            const privateKey = privateKeys[index]
+            const privateKey = privateKeys[index] ? privateKeys[index] : privateKeys[0]
             const privateKeyBuffer = Buffer.from(base58.decode(privateKey))
 
             const transactionUniqueFulfillment = input.fulfills ? serializedTransaction