diff --git a/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/org/apache/dubbo/rpc/protocol/dubbo/CallbackServiceCodec.java b/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/org/apache/dubbo/rpc/protocol/dubbo/CallbackServiceCodec.java
index 02b4e8c287..332dff5cac 100644
--- a/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/org/apache/dubbo/rpc/protocol/dubbo/CallbackServiceCodec.java
+++ b/dubbo-rpc/dubbo-rpc-dubbo/src/main/java/org/apache/dubbo/rpc/protocol/dubbo/CallbackServiceCodec.java
@@ -116,7 +116,7 @@ public class CallbackServiceCodec {
         params.put(IS_SERVER_KEY, Boolean.FALSE.toString());
         // mark it's a callback, for troubleshooting
         params.put(IS_CALLBACK_SERVICE, Boolean.TRUE.toString());
-        String group = (url == null ? null : url.getGroup());
+        String group = (inv == null ? null : (String) inv.getObjectAttachment(GROUP_KEY));
         if (group != null && group.length() > 0) {
             params.put(GROUP_KEY, group);
         }
@@ -266,7 +266,7 @@ public class CallbackServiceCodec {
         if (count != null && count >= limit) {
             //client side error
             throw new IllegalStateException("interface " + interfaceClass + " `s callback instances num exceed providers limit :" + limit
-                    + " ,current num: " + (count + 1) + ". The new callback service will not work !!! you can cancle the callback service which exported before. channel :" + channel);
+                + " ,current num: " + (count + 1) + ". The new callback service will not work !!! you can cancle the callback service which exported before. channel :" + channel);
         } else {
             return false;
         }
@@ -309,10 +309,10 @@ public class CallbackServiceCodec {
         Class<?>[] pts = inv.getParameterTypes();
         switch (callbackStatus) {
             case CallbackServiceCodec.CALLBACK_CREATE:
-                inv.setAttachment(INV_ATT_CALLBACK_KEY + paraIndex, exportOrUnexportCallbackService(channel, inv,  url, pts[paraIndex], args[paraIndex], true));
+                inv.setAttachment(INV_ATT_CALLBACK_KEY + paraIndex, exportOrUnexportCallbackService(channel, inv, url, pts[paraIndex], args[paraIndex], true));
                 return null;
             case CallbackServiceCodec.CALLBACK_DESTROY:
-                inv.setAttachment(INV_ATT_CALLBACK_KEY + paraIndex, exportOrUnexportCallbackService(channel, inv,  url, pts[paraIndex], args[paraIndex], false));
+                inv.setAttachment(INV_ATT_CALLBACK_KEY + paraIndex, exportOrUnexportCallbackService(channel, inv, url, pts[paraIndex], args[paraIndex], false));
                 return null;
             default:
                 return args[paraIndex];