diff --git a/NodeSetToAML.cs b/NodeSetToAML.cs
index e9e33c1..0a1ef60 100644
--- a/NodeSetToAML.cs
+++ b/NodeSetToAML.cs
@@ -3440,6 +3440,12 @@ private void AddStructureFieldDefinition( AttributeFamilyType attribute, UANode
                                         RemoveUnwantedAttribute(descriptionCreated,"StructureFieldDefinition");
                                     }
 
+                                    if ( field.AllowSubTypes)
+                                    {
+                                        AddModifyAttribute(structureFieldAttribute.Attribute,
+                                            "AllowSubTypes", "Boolean", new Variant(true));
+                                    }
+
                                     // Remove the NodeId from the structure Field
                                     AttributeType nodeIdAttribute = structureFieldAttribute.Attribute[ "DataType" ];
                                     if( nodeIdAttribute != null )
diff --git a/SystemTest/TestStructureFieldDefinition.cs b/SystemTest/TestStructureFieldDefinition.cs
index 079c178..f788c33 100644
--- a/SystemTest/TestStructureFieldDefinition.cs
+++ b/SystemTest/TestStructureFieldDefinition.cs
@@ -55,6 +55,7 @@ public void TestUnwantedAttributes(TestHelper.Uris uriId, uint nodeId)
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "QosCategory", "ArrayDimensions", null, "", "")]
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "QosCategory", "MaxStringLength", "123", "", "")]
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "QosCategory", "IsOptional", "true", "", "")]
+        [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "QosCategory", "AllowSubTypes", null, "", "")]
 
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "DatagramQos", "Name", null, "", "")]
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "DatagramQos", "Description", "Transmit Quality of Service", "0", "")]
@@ -62,6 +63,7 @@ public void TestUnwantedAttributes(TestHelper.Uris uriId, uint nodeId)
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "DatagramQos", "ArrayDimensions", "3", "1", "")]
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "DatagramQos", "ValueRank", "2", "", "")]
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "DatagramQos", "IsOptional", null, "", "")]
+        [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "DatagramQos", "AllowSubTypes", "true", "", "")]
 
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "NoDescription", "Name", null, "", "")]
         [DataRow(TestHelper.Uris.Test, PublisherQosDataType, "NoDescription", "Description", null, "", "")]