diff --git a/src/NHibernate.Test/Async/NHSpecificTest/GH1439/Fixture.cs b/src/NHibernate.Test/Async/NHSpecificTest/GH1439/Fixture.cs
new file mode 100644
index 00000000000..0962d06c353
--- /dev/null
+++ b/src/NHibernate.Test/Async/NHSpecificTest/GH1439/Fixture.cs
@@ -0,0 +1,131 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by AsyncGenerator.
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Intercept;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+using NHibernate.Linq;
+
+namespace NHibernate.Test.NHSpecificTest.GH1439
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class FixtureAsync : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<CompositeEntity>(rc =>
+			{
+				rc.ComposedId(
+					c =>
+					{
+						c.Property(t => t.Id);
+						c.Property(t => t.Name);
+					});
+
+				rc.Property(x => x.LazyProperty, x => x.Lazy(true));
+			});
+
+			mapper.Class<EntityWithComponentId>(rc =>
+			{
+				rc.ComponentAsId(e => e.Id, map =>
+				{
+					map.Property(c => c.Id);
+					map.Property(c => c.Name);
+				});
+
+				rc.Property(e => e.LazyProperty, map => map.Lazy(true));
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new CompositeEntity { Id = 1, Name = "Bob", LazyProperty = "LazyProperty"};
+				session.Save(e1);
+				var e2 = new EntityWithComponentId
+					{ Id = new ComponentId { Id = 1, Name = "Bob" }, LazyProperty = "LazyProperty" };
+				session.Save(e2);
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		[KnownBug("#1439")]
+		public async Task LazyPropertyShouldBeUninitializedAndLoadableAsync()
+		{
+			using (var session = OpenSession())
+			using (var tran = session.BeginTransaction())
+			{
+				var e1 = await (session.Query<CompositeEntity>().SingleAsync());
+				Assert.Multiple(
+					() =>
+					{
+						Assert.That(
+							NHibernateUtil.IsPropertyInitialized(e1, nameof(CompositeEntity.LazyProperty)),
+							Is.False,
+							"Lazy property initialization status");
+						Assert.That(
+							FieldInterceptionHelper.IsInstrumented(e1),
+							Is.True,
+							"Entity IsInstrumented");
+						Assert.That(
+							e1,
+							Has.Property(nameof(CompositeEntity.LazyProperty)).EqualTo("LazyProperty"));
+					});
+				await (tran.CommitAsync());
+			}
+		}
+
+		[Test]
+		public async Task LazyPropertyShouldBeUninitializedAndLoadableWithComponentIdAsync()
+		{
+			using (var session = OpenSession())
+			using (var tran = session.BeginTransaction())
+			{
+				var e2 = await (session.Query<EntityWithComponentId>().SingleAsync());
+				Assert.Multiple(
+					() =>
+					{
+						Assert.That(
+							NHibernateUtil.IsPropertyInitialized(e2, nameof(CompositeEntity.LazyProperty)),
+							Is.False,
+							"Lazy property initialization status");
+						Assert.That(
+							FieldInterceptionHelper.IsInstrumented(e2),
+							Is.True,
+							"Entity IsInstrumented");
+						Assert.That(
+							e2,
+							Has.Property(nameof(CompositeEntity.LazyProperty)).EqualTo("LazyProperty"));
+					});
+				await (tran.CommitAsync());
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH1439/CompositeEntity.cs b/src/NHibernate.Test/NHSpecificTest/GH1439/CompositeEntity.cs
new file mode 100644
index 00000000000..0b0e4477a21
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH1439/CompositeEntity.cs
@@ -0,0 +1,31 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH1439
+{
+	public class CompositeEntity : IEquatable<CompositeEntity>
+	{
+		public virtual int Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual string LazyProperty { get; set; }
+
+		public virtual bool Equals(CompositeEntity other)
+		{
+			if (ReferenceEquals(null, other)) return false;
+			if (ReferenceEquals(this, other)) return true;
+			return Id == other.Id && string.Equals(Name, other.Name);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return Equals(obj as CompositeEntity);
+		}
+
+		public override int GetHashCode()
+		{
+			unchecked
+			{
+				return (Id * 397) ^ (Name != null ? Name.GetHashCode() : 0);
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH1439/EntityWithComponentId.cs b/src/NHibernate.Test/NHSpecificTest/GH1439/EntityWithComponentId.cs
new file mode 100644
index 00000000000..2b8263161ed
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH1439/EntityWithComponentId.cs
@@ -0,0 +1,36 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH1439
+{
+	public class EntityWithComponentId
+	{
+		public virtual ComponentId Id { get; set; }
+		public virtual string LazyProperty { get; set; }
+	}
+
+	public class ComponentId : IEquatable<ComponentId>
+	{
+		public int Id { get; set; }
+		public string Name { get; set; }
+
+		public bool Equals(ComponentId other)
+		{
+			if (ReferenceEquals(null, other)) return false;
+			if (ReferenceEquals(this, other)) return true;
+			return Id == other.Id && string.Equals(Name, other.Name);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return Equals(obj as ComponentId);
+		}
+
+		public override int GetHashCode()
+		{
+			unchecked
+			{
+				return (Id * 397) ^ (Name != null ? Name.GetHashCode() : 0);
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH1439/Fixture.cs b/src/NHibernate.Test/NHSpecificTest/GH1439/Fixture.cs
new file mode 100644
index 00000000000..5a12bfe77fe
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH1439/Fixture.cs
@@ -0,0 +1,119 @@
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Intercept;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH1439
+{
+	[TestFixture]
+	public class Fixture : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<CompositeEntity>(rc =>
+			{
+				rc.ComposedId(
+					c =>
+					{
+						c.Property(t => t.Id);
+						c.Property(t => t.Name);
+					});
+
+				rc.Property(x => x.LazyProperty, x => x.Lazy(true));
+			});
+
+			mapper.Class<EntityWithComponentId>(rc =>
+			{
+				rc.ComponentAsId(e => e.Id, map =>
+				{
+					map.Property(c => c.Id);
+					map.Property(c => c.Name);
+				});
+
+				rc.Property(e => e.LazyProperty, map => map.Lazy(true));
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new CompositeEntity { Id = 1, Name = "Bob", LazyProperty = "LazyProperty"};
+				session.Save(e1);
+				var e2 = new EntityWithComponentId
+					{ Id = new ComponentId { Id = 1, Name = "Bob" }, LazyProperty = "LazyProperty" };
+				session.Save(e2);
+				transaction.Commit();
+			}
+		}
+
+		protected override void OnTearDown()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				session.CreateQuery("delete from System.Object").ExecuteUpdate();
+				transaction.Commit();
+			}
+		}
+
+		[Test]
+		[KnownBug("#1439")]
+		public void LazyPropertyShouldBeUninitializedAndLoadable()
+		{
+			using (var session = OpenSession())
+			using (var tran = session.BeginTransaction())
+			{
+				var e1 = session.Query<CompositeEntity>().Single();
+				Assert.Multiple(
+					() =>
+					{
+						Assert.That(
+							NHibernateUtil.IsPropertyInitialized(e1, nameof(CompositeEntity.LazyProperty)),
+							Is.False,
+							"Lazy property initialization status");
+						Assert.That(
+							FieldInterceptionHelper.IsInstrumented(e1),
+							Is.True,
+							"Entity IsInstrumented");
+						Assert.That(
+							e1,
+							Has.Property(nameof(CompositeEntity.LazyProperty)).EqualTo("LazyProperty"));
+					});
+				tran.Commit();
+			}
+		}
+
+		[Test]
+		public void LazyPropertyShouldBeUninitializedAndLoadableWithComponentId()
+		{
+			using (var session = OpenSession())
+			using (var tran = session.BeginTransaction())
+			{
+				var e2 = session.Query<EntityWithComponentId>().Single();
+				Assert.Multiple(
+					() =>
+					{
+						Assert.That(
+							NHibernateUtil.IsPropertyInitialized(e2, nameof(CompositeEntity.LazyProperty)),
+							Is.False,
+							"Lazy property initialization status");
+						Assert.That(
+							FieldInterceptionHelper.IsInstrumented(e2),
+							Is.True,
+							"Entity IsInstrumented");
+						Assert.That(
+							e2,
+							Has.Property(nameof(CompositeEntity.LazyProperty)).EqualTo("LazyProperty"));
+					});
+				tran.Commit();
+			}
+		}
+	}
+}