diff --git a/src/main/java/tccn/zhub/RpcResult.java b/src/main/java/tccn/zhub/RpcResult.java
index 767e2c0..8d3858b 100644
--- a/src/main/java/tccn/zhub/RpcResult.java
+++ b/src/main/java/tccn/zhub/RpcResult.java
@@ -34,7 +34,7 @@ public class RpcResult<R> {
         return result;
     }
 
-    public void setResult(Object result) {
-        this.result = (R) result;
+    public void setResult(R result) {
+        this.result = result;
     }
 }
diff --git a/src/main/java/tccn/zhub/ZHubClient.java b/src/main/java/tccn/zhub/ZHubClient.java
index a67c943..5f12efc 100644
--- a/src/main/java/tccn/zhub/ZHubClient.java
+++ b/src/main/java/tccn/zhub/ZHubClient.java
@@ -638,7 +638,7 @@ public class ZHubClient extends AbstractConsumer implements IConsumer, IProducer
             TypeToken typeToken = rpc.getTypeToken();
             if (typeToken.getType() != ((RpcResult<?>) value).getResult().getClass()) {
                 Object result = gson.fromJson(toStr(((RpcResult<?>) value).getResult()), typeToken.getType());
-                ((RpcResult<?>) value).setResult(result);
+                ((RpcResult<Object>) value).setResult(result);
             }
 
             rpc.setRpcResult((RpcResult) value);