diff --git a/protocol/src/main/java/com/zfoo/protocol/util/ReflectionUtils.java b/protocol/src/main/java/com/zfoo/protocol/util/ReflectionUtils.java
index 3ce66b56..24fa8bf2 100644
--- a/protocol/src/main/java/com/zfoo/protocol/util/ReflectionUtils.java
+++ b/protocol/src/main/java/com/zfoo/protocol/util/ReflectionUtils.java
@@ -64,7 +64,7 @@ public abstract class ReflectionUtils {
         // Keep backing up the inheritance hierarchy.
         Class<?> targetClass = clazz;
         do {
-            var fields = clazz.getDeclaredFields();
+            var fields = targetClass.getDeclaredFields();
             for (var field : fields) {
                 ReflectionUtils.filterField(field, fieldFilter, fieldCallback);
             }