diff --git a/src/NHibernate.Test/Async/NHSpecificTest/GH2707/FixtureByCode.cs b/src/NHibernate.Test/Async/NHSpecificTest/GH2707/FixtureByCode.cs
new file mode 100644
index 00000000000..ed8a151bd42
--- /dev/null
+++ b/src/NHibernate.Test/Async/NHSpecificTest/GH2707/FixtureByCode.cs
@@ -0,0 +1,72 @@
+//------------------------------------------------------------------------------
+// <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.Mapping.ByCode;
+using NUnit.Framework;
+using NHibernate.Linq;
+
+namespace NHibernate.Test.NHSpecificTest.GH2707
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class ConditionalFixtureAsync : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.AddMapping<Entity1Map>();
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new Entity1() {Id = "id1", IsChiusa = true};
+				e1.CustomType = new MyType() {ToPersist = 1};
+				session.Save(e1);
+				var e2 = new Entity1() {Id = "id2", IsChiusa = false};
+				session.Save(e2);
+				e1.Parent = 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 EntityAndCustomTypeInConditionalResultAsync()
+		{
+			using (var s = OpenSession())
+				await ((from x in s.Query<Entity1>()
+				let parent = x.Parent
+				//NH-3005 - Contditional on custom type
+				where (parent.IsChiusa ? x.CustomType : parent.CustomType) == x.CustomType
+				select new
+				{
+					ParentIsChiusa = (((x == null) ? null : x.Parent) == null)
+						? (bool?) null
+						: x.Parent.IsChiusa,
+				}).ToListAsync());
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH2707/Entity.cs b/src/NHibernate.Test/NHSpecificTest/GH2707/Entity.cs
new file mode 100644
index 00000000000..46d557151d7
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH2707/Entity.cs
@@ -0,0 +1,139 @@
+using System;
+using System.Data.Common;
+using NHibernate.Engine;
+using NHibernate.Mapping.ByCode.Conformist;
+using NHibernate.SqlTypes;
+using NHibernate.UserTypes;
+
+namespace NHibernate.Test.NHSpecificTest.GH2707
+{
+	public class Entity1
+	{
+		public virtual string Id { get; set; }
+		public virtual bool IsChiusa { get; set; }
+		public virtual MyType CustomType { get; set; }
+		public virtual Entity1 Parent { get; set; }
+	}
+
+	class Entity1Map : ClassMapping<Entity1>
+	{
+		public Entity1Map()
+		{
+			Table("TA");
+
+			Id(x => x.Id);
+			Property(x => x.IsChiusa);
+			Property(x => x.CustomType, m => m.Type<SimpleCustomType>());
+			ManyToOne(x => x.Parent, x => x.ForeignKey("none"));
+		}
+	}
+
+	public class MyType
+	{
+		public int ToPersist { get; set; }
+
+		public override bool Equals(object obj)
+		{
+			if (obj == null || GetType() != obj.GetType())
+			{
+				return false;
+			}
+
+			var other = (MyType) obj;
+			return ToPersist == other.ToPersist;
+		}
+
+		public override int GetHashCode()
+		{
+			return ToPersist.GetHashCode();
+		}
+	}
+
+	public class SimpleCustomType : IUserType
+	{
+		private static readonly SqlType[] ReturnSqlTypes = {SqlTypeFactory.Int32};
+
+		#region IUserType Members
+
+		public new bool Equals(object x, object y)
+		{
+			if (ReferenceEquals(x, y))
+			{
+				return true;
+			}
+
+			if (ReferenceEquals(null, x) || ReferenceEquals(null, y))
+			{
+				return false;
+			}
+
+			return x.Equals(y);
+		}
+
+		public int GetHashCode(object x)
+		{
+			return (x == null) ? 0 : x.GetHashCode();
+		}
+
+		public SqlType[] SqlTypes
+		{
+			get { return ReturnSqlTypes; }
+		}
+
+		public object DeepCopy(object value)
+		{
+			return value;
+		}
+
+		public void NullSafeSet(DbCommand cmd, object value, int index, ISessionImplementor session)
+		{
+			if (value == null)
+			{
+				cmd.Parameters[index].Value = DBNull.Value;
+			}
+			else
+			{
+				cmd.Parameters[index].Value = ((MyType) value).ToPersist;
+			}
+		}
+
+		public System.Type ReturnedType
+		{
+			get { return typeof(Int32); }
+		}
+
+		public object NullSafeGet(DbDataReader rs, string[] names, ISessionImplementor session, object owner)
+		{
+			int index0 = rs.GetOrdinal(names[0]);
+			if (rs.IsDBNull(index0))
+			{
+				return null;
+			}
+
+			int value = rs.GetInt32(index0);
+			return new MyType {ToPersist = value};
+		}
+
+		public bool IsMutable
+		{
+			get { return false; }
+		}
+
+		public object Replace(object original, object target, object owner)
+		{
+			return original;
+		}
+
+		public object Assemble(object cached, object owner)
+		{
+			return cached;
+		}
+
+		public object Disassemble(object value)
+		{
+			return value;
+		}
+
+		#endregion
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH2707/FixtureByCode.cs b/src/NHibernate.Test/NHSpecificTest/GH2707/FixtureByCode.cs
new file mode 100644
index 00000000000..36809f21220
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH2707/FixtureByCode.cs
@@ -0,0 +1,60 @@
+using System.Linq;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2707
+{
+	[TestFixture]
+	public class ConditionalFixture : TestCaseMappingByCode
+	{
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.AddMapping<Entity1Map>();
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var e1 = new Entity1() {Id = "id1", IsChiusa = true};
+				e1.CustomType = new MyType() {ToPersist = 1};
+				session.Save(e1);
+				var e2 = new Entity1() {Id = "id2", IsChiusa = false};
+				session.Save(e2);
+				e1.Parent = 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 EntityAndCustomTypeInConditionalResult()
+		{
+			using (var s = OpenSession())
+				(from x in s.Query<Entity1>()
+				let parent = x.Parent
+				//NH-3005 - Conditional with custom type
+				where (parent.IsChiusa ? x.CustomType : parent.CustomType) == x.CustomType
+				select new
+				{
+					ParentIsChiusa = (((x == null) ? null : x.Parent) == null)
+						? (bool?) null
+						: x.Parent.IsChiusa,
+				}).ToList();
+		}
+	}
+}
diff --git a/src/NHibernate/Linq/Visitors/HqlGeneratorExpressionVisitor.cs b/src/NHibernate/Linq/Visitors/HqlGeneratorExpressionVisitor.cs
index 2a285ff5311..63d9d3e2a1e 100644
--- a/src/NHibernate/Linq/Visitors/HqlGeneratorExpressionVisitor.cs
+++ b/src/NHibernate/Linq/Visitors/HqlGeneratorExpressionVisitor.cs
@@ -622,7 +622,7 @@ protected HqlTreeNode VisitConditionalExpression(ConditionalExpression expressio
 			// If both operands are parameters, HQL will not be able to determine the resulting type before
 			// parameters binding. But it has to compute result set columns type before parameters are bound,
 			// so an artificial cast is introduced to hint HQL at the resulting type.
-			return expression.Type == typeof(bool) || expression.Type == typeof(bool?)
+			return expression.Type == typeof(bool) || expression.Type == typeof(bool?) || !HqlIdent.SupportsType(expression.Type)
 				? @case
 				: _hqlTreeBuilder.TransparentCast(@case, expression.Type);
 		}