diff --git a/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/polymorphism/JsonbPolymorphismTest.java b/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/polymorphism/JsonbPolymorphismTest.java
index 87d8389..5235143 100644
--- a/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/polymorphism/JsonbPolymorphismTest.java
+++ b/johnzon-jsonb/src/test/java/org/apache/johnzon/jsonb/polymorphism/JsonbPolymorphismTest.java
@@ -42,6 +42,17 @@
     @Rule public JsonbRule jsonb = new JsonbRule();
 
     @Test
+    public void testNestedSerialization() {
+        Labrador labrador = new Labrador();
+        labrador.dogAge = 3;
+        labrador.labradorName = "john";
+        AnimalWrapper wrapper = new AnimalWrapper();
+        wrapper.animal = labrador;
+
+        assertEquals("{\"animal\":{\"@animal\":\"dog\",\"@dog\":\"labrador\",\"dogAge\":3,\"labradorName\":\"john\"}}", jsonb.toJson(wrapper));
+    }
+
+    @Test
     public void testSerialization() {
         Labrador labrador = new Labrador();
         labrador.dogAge = 3;
@@ -100,6 +111,10 @@
 
     }
 
+    public static class AnimalWrapper {
+        public Animal animal;
+    }
+
     @JsonbTypeInfo(key = "@animal", value = @JsonbSubtype(alias = "dog", type = Dog.class))
     public interface Animal {
     }
diff --git a/johnzon-mapper/src/main/java/org/apache/johnzon/mapper/MappingGeneratorImpl.java b/johnzon-mapper/src/main/java/org/apache/johnzon/mapper/MappingGeneratorImpl.java
index cf44c5c..c06f38d 100644
--- a/johnzon-mapper/src/main/java/org/apache/johnzon/mapper/MappingGeneratorImpl.java
+++ b/johnzon-mapper/src/main/java/org/apache/johnzon/mapper/MappingGeneratorImpl.java
@@ -192,12 +192,6 @@
                     generator.writeStartObject();
                 }
 
-                if (classMapping.serializedPolymorphicProperties != null) {
-                    for (Map.Entry<String, String> polymorphicProperty : classMapping.serializedPolymorphicProperties) {
-                        generator.write(polymorphicProperty.getKey(), polymorphicProperty.getValue());
-                    }
-                }
-
                 final boolean writeEnd = doWriteObjectBody(object, ignoredProperties, jsonPointer, generator);
                 if (writeEnd && writeBody) {
                     generator.writeEnd();
@@ -376,6 +370,12 @@
             return true;
         }
 
+        if (classMapping.serializedPolymorphicProperties != null) {
+            for (Map.Entry<String, String> polymorphicProperty : classMapping.serializedPolymorphicProperties) {
+                generator.write(polymorphicProperty.getKey(), polymorphicProperty.getValue());
+            }
+        }
+
         for (final Map.Entry<String, Mappings.Getter> getterEntry : classMapping.getters.entrySet()) {
             final Mappings.Getter getter = getterEntry.getValue();
             if (ignored != null && ignored.contains(getterEntry.getKey())) {