diff --git a/src/zutil/ClassUtil.java b/src/zutil/ClassUtil.java
index cb23216..72c3cc6 100755
--- a/src/zutil/ClassUtil.java
+++ b/src/zutil/ClassUtil.java
@@ -239,7 +239,11 @@ public class ClassUtil {
         List<Field> fields = new ArrayList<>();
 
         for (Class<?> currentClass = clazz; currentClass != upToClass; currentClass = currentClass.getSuperclass()) {
-            Collections.addAll(fields, currentClass.getDeclaredFields());
+            for (Field field : currentClass.getDeclaredFields()) {
+                if (!field.isSynthetic()) {
+                    fields.add(field);
+                }
+            }
         }
 
         return fields;