diff --git a/src/NHibernate.Test/Async/NHSpecificTest/GH2820/FixtureByCode.cs b/src/NHibernate.Test/Async/NHSpecificTest/GH2820/FixtureByCode.cs
new file mode 100644
index 00000000000..765f0657908
--- /dev/null
+++ b/src/NHibernate.Test/Async/NHSpecificTest/GH2820/FixtureByCode.cs
@@ -0,0 +1,79 @@
+//------------------------------------------------------------------------------
+// <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;
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Dialect;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+using NHibernate.Linq;
+
+namespace NHibernate.Test.NHSpecificTest.GH2820
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class PostgresTimestampzFixtureAsync : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+			mapper.Class<Entity>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.Property(x => x.Timestamp, m => m.Column(x => x.SqlType("timestamp with time zone")));
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			return dialect is PostgreSQLDialect;
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new Entity {Name = "Bob", Timestamp = DateTimeOffset.UtcNow};
+				session.Save(e1);
+
+				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]
+		public async Task CanRetrieveEntityWithTimeStampColumnAsync()
+		{
+			using (var session = OpenSession())
+			{
+				var result = from e in session.Query<Entity>()
+							 where e.Name == "Bob"
+							 select e;
+
+				Assert.That(await (result.ToListAsync()), Has.Count.EqualTo(1));
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH2820/Entity.cs b/src/NHibernate.Test/NHSpecificTest/GH2820/Entity.cs
new file mode 100644
index 00000000000..87261e3239b
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH2820/Entity.cs
@@ -0,0 +1,11 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH2820
+{
+	class Entity
+	{
+		public virtual Guid Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual DateTimeOffset Timestamp { get; set; }
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH2820/FixtureByCode.cs b/src/NHibernate.Test/NHSpecificTest/GH2820/FixtureByCode.cs
new file mode 100644
index 00000000000..f8e196cd0e6
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH2820/FixtureByCode.cs
@@ -0,0 +1,67 @@
+using System;
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Dialect;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2820
+{
+	[TestFixture]
+	public class PostgresTimestampzFixture : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+			mapper.Class<Entity>(rc =>
+			{
+				rc.Id(x => x.Id, m => m.Generator(Generators.GuidComb));
+				rc.Property(x => x.Name);
+				rc.Property(x => x.Timestamp, m => m.Column(x => x.SqlType("timestamp with time zone")));
+			});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override bool AppliesTo(Dialect.Dialect dialect)
+		{
+			return dialect is PostgreSQLDialect;
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new Entity {Name = "Bob", Timestamp = DateTimeOffset.UtcNow};
+				session.Save(e1);
+
+				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]
+		public void CanRetrieveEntityWithTimeStampColumn()
+		{
+			using (var session = OpenSession())
+			{
+				var result = from e in session.Query<Entity>()
+							 where e.Name == "Bob"
+							 select e;
+
+				Assert.That(result.ToList(), Has.Count.EqualTo(1));
+			}
+		}
+	}
+}