diff --git a/redisson/src/main/java/org/redisson/RedissonLiveObjectService.java b/redisson/src/main/java/org/redisson/RedissonLiveObjectService.java
index 1bad81e49..414880c92 100644
--- a/redisson/src/main/java/org/redisson/RedissonLiveObjectService.java
+++ b/redisson/src/main/java/org/redisson/RedissonLiveObjectService.java
@@ -174,6 +174,7 @@ public class RedissonLiveObjectService implements RLiveObjectService {
     @Override
     public <T> T merge(T detachedObject) {
         T attachedObject = attach(detachedObject);
+        getMap(attachedObject).fastPut("redisson_live_object", "1");
         copy(detachedObject, attachedObject);
         return attachedObject;
     }
@@ -388,6 +389,13 @@ public class RedissonLiveObjectService implements RLiveObjectService {
     }
 
     private <T> void copy(T detachedObject, T attachedObject) {
+        for (FieldDescription.InDefinedShape field : Introspectior.getFieldsDescription(detachedObject.getClass())) {
+            Object object = ClassUtils.getField(detachedObject, field.getName());
+            if (object != null && object.getClass().isAnnotationPresent(REntity.class)) {
+                throw new IllegalArgumentException("REntity should be attached to Redisson before save");
+            }
+
+        }
 //        for (FieldDescription.InDefinedShape field : Introspectior.getFieldsDescription(detachedObject.getClass())) {
 //            Object obj = ClassUtils.getField(detachedObject, field.getName());
 //            if (obj instanceof SortedSet) {
diff --git a/redisson/src/main/java/org/redisson/liveobject/misc/Introspectior.java b/redisson/src/main/java/org/redisson/liveobject/misc/Introspectior.java
index c13c398ff..01c9f9d3a 100644
--- a/redisson/src/main/java/org/redisson/liveobject/misc/Introspectior.java
+++ b/redisson/src/main/java/org/redisson/liveobject/misc/Introspectior.java
@@ -28,11 +28,11 @@ import net.bytebuddy.matcher.ElementMatchers;
  */
 public class Introspectior {
 
-    public static TypeDescription.ForLoadedType getTypeDescription(Class c) {
+    public static TypeDescription.ForLoadedType getTypeDescription(Class<?> c) {
         return new TypeDescription.ForLoadedType(c);
     }
 
-    public static MethodDescription getMethodDescription(Class c, String method) {
+    public static MethodDescription getMethodDescription(Class<?> c, String method) {
         if (method == null || method.isEmpty()) {
             return null;
         }
@@ -42,7 +42,13 @@ public class Introspectior {
                 .getOnly();
     }
 
-    public static FieldDescription getFieldDescription(Class c, String field) {
+    public static FieldList<FieldDescription.InDefinedShape> getFieldsDescription(Class<?> c) {
+        return getTypeDescription(c)
+                .getDeclaredFields();
+                
+    }
+    
+    public static FieldDescription getFieldDescription(Class<?> c, String field) {
         if (field == null || field.isEmpty()) {
             return null;
         }
@@ -52,7 +58,7 @@ public class Introspectior {
                 .getOnly();
     }
 
-    public static FieldList<FieldDescription.InDefinedShape> getFieldsWithAnnotation(Class c, Class<? extends Annotation> a) {
+    public static FieldList<FieldDescription.InDefinedShape> getFieldsWithAnnotation(Class<?> c, Class<? extends Annotation> a) {
         return getTypeDescription(c)
                 .getDeclaredFields()
                 .filter(ElementMatchers.isAnnotatedWith(a));
diff --git a/redisson/src/test/java/org/redisson/RedissonLiveObjectServiceTest.java b/redisson/src/test/java/org/redisson/RedissonLiveObjectServiceTest.java
index 1e027cec6..d84634e51 100644
--- a/redisson/src/test/java/org/redisson/RedissonLiveObjectServiceTest.java
+++ b/redisson/src/test/java/org/redisson/RedissonLiveObjectServiceTest.java
@@ -579,6 +579,7 @@ public class RedissonLiveObjectServiceTest extends BaseTest {
         assertEquals("VALUE", merged.getValue());
         try {
             service.persist(ts);
+            fail("Should not be here");
         } catch (Exception e) {
             assertEquals("This REntity already exists.", e.getMessage());
         }
@@ -1188,6 +1189,14 @@ public class RedissonLiveObjectServiceTest extends BaseTest {
         
         private Customer customer;
         
+        public Order() {
+        }
+        
+        public Order(Customer customer) {
+            super();
+            this.customer = customer;
+        }
+
         public void setCustomer(Customer customer) {
             this.customer = customer;
         }
@@ -1210,6 +1219,13 @@ public class RedissonLiveObjectServiceTest extends BaseTest {
         customer.getOrders().add(order);
     }
     
+    @Test(expected = IllegalArgumentException.class)
+    public void testObjectShouldNotBeAttached2() {
+        Customer customer = new Customer("12");
+        Order order = new Order(customer);
+        order = redisson.getLiveObjectService().persist(order);
+    }
+    
     @Test
     public void testObjectShouldBeAttached() {
         Customer customer = new Customer("12");
@@ -1261,7 +1277,6 @@ public class RedissonLiveObjectServiceTest extends BaseTest {
         private String name;
 
         protected ClassWithoutIdSetterGetter() {
-            System.out.println("123");
         }
         
         public ClassWithoutIdSetterGetter(String name) {