diff --git a/backend/tests/Squidex.Infrastructure.Tests/DomainIdTests.cs b/backend/tests/Squidex.Infrastructure.Tests/DomainIdTests.cs
index 0e27454b5..99a800cde 100644
--- a/backend/tests/Squidex.Infrastructure.Tests/DomainIdTests.cs
+++ b/backend/tests/Squidex.Infrastructure.Tests/DomainIdTests.cs
@@ -8,6 +8,8 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Runtime.Serialization;
+using FluentAssertions;
 using Squidex.Infrastructure.TestHelpers;
 using Xunit;
 
@@ -17,6 +19,21 @@ namespace Squidex.Infrastructure
     {
         private readonly TypeConverter typeConverter = TypeDescriptor.GetConverter(typeof(DomainId));
 
+        public class MyTest
+        {
+            [IgnoreDataMember]
+            public DomainId Calculated
+            {
+                get { return DomainId.Combine(Id0, Id1.Id); }
+            }
+
+            public DomainId Id0 { get; set; }
+
+            public NamedId<DomainId> Id1 { get; set; }
+
+            public NamedId<DomainId> Id2 { get; set; }
+        }
+
         [Fact]
         public void Should_initialize_default()
         {
@@ -160,5 +177,20 @@ namespace Squidex.Infrastructure
 
             Assert.Equal(321, serialized[DomainId.Create("123")]);
         }
+
+        [Fact]
+        public void Should_serialize_and_deserialize_in_object()
+        {
+            var obj = new MyTest
+            {
+                Id0 = DomainId.NewGuid(),
+                Id1 = NamedId.Of(DomainId.NewGuid(), "1"),
+                Id2 = NamedId.Of(DomainId.NewGuid(), "2")
+            };
+
+            var serialized = obj.SerializeAndDeserialize();
+
+            serialized.Should().BeEquivalentTo(obj);
+        }
     }
 }
diff --git a/backend/tests/Squidex.Infrastructure.Tests/TestHelpers/JsonHelper.cs b/backend/tests/Squidex.Infrastructure.Tests/TestHelpers/JsonHelper.cs
index 0ea47b255..371965abd 100644
--- a/backend/tests/Squidex.Infrastructure.Tests/TestHelpers/JsonHelper.cs
+++ b/backend/tests/Squidex.Infrastructure.Tests/TestHelpers/JsonHelper.cs
@@ -40,6 +40,7 @@ namespace Squidex.Infrastructure.TestHelpers
                     new InstantConverter(),
                     new JsonValueConverter(),
                     new LanguageConverter(),
+                    new NamedDomainIdConverter(),
                     new NamedGuidIdConverter(),
                     new NamedLongIdConverter(),
                     new NamedStringIdConverter(),