diff --git a/lib/index.js b/lib/index.js
index f94cf17..5b10ff9 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -241,6 +241,7 @@ RpcClient.callspec = {
   getSpentInfo: 'obj',
   getSuperBlockBudget: 'int',
   getTransaction: '',
+  getTxChainLocks: 'array',
   getTxOut: 'str int bool',
   getTxOutProof: 'str str',
   getTxOutSetInfo: '',
@@ -385,6 +386,12 @@ function generateRPCMethods(constructor, apiCalls, rpc) {
       }
       return arg;
     },
+    array(arg) {
+      if (typeof arg === 'string') {
+        return JSON.parse(arg);
+      }
+      return arg;
+    },
   };
 
   for (const k in apiCalls) {