diff --git a/lib/RpcClient.js b/lib/RpcClient.js
index 8d506bb..490f528 100644
--- a/lib/RpcClient.js
+++ b/lib/RpcClient.js
@@ -33,6 +33,7 @@ var callspec = {
   decodeRawTransaction: '',
   dumpPrivKey: '',
   encryptWallet: '',
+  estimateFee: 'int',
   getAccount: '',
   getAccountAddress: 'str',
   getAddedNodeInfo: '',