diff --git a/src/NHibernate.Test/MappingByCode/ExplicitMappingTests/BasicMappingOfSimpleClass.cs b/src/NHibernate.Test/MappingByCode/ExplicitMappingTests/BasicMappingOfSimpleClass.cs
index 78f681a286b..f667019f8e7 100644
--- a/src/NHibernate.Test/MappingByCode/ExplicitMappingTests/BasicMappingOfSimpleClass.cs
+++ b/src/NHibernate.Test/MappingByCode/ExplicitMappingTests/BasicMappingOfSimpleClass.cs
@@ -6,7 +6,7 @@
 using NHibernate.Mapping.ByCode;
 using NUnit.Framework;
 
-namespace NHibernate.Test.MappingByCode.ExpliticMappingTests
+namespace NHibernate.Test.MappingByCode.ExplicitMappingTests
 {
 	public class BasicMappingOfSimpleClass
 	{
@@ -16,6 +16,25 @@ public class MyClass
 			public string Something { get; set; }
 		}
 
+		[Test]
+		public void AbstractClass()
+		{
+			//NH-3527
+			var mapper = new ModelMapper();
+			mapper.Class<MyClass>(ca =>
+			{
+				ca.Abstract(true);
+				ca.Id(x => x.Id, map =>
+				{
+					map.Column("MyClassId");
+					map.Generator(Generators.HighLow, gmap => gmap.Params(new { max_low = 100 }));
+				});
+				ca.Property(x => x.Something, map => map.Length(150));
+			});
+			var hbmMapping = mapper.CompileMappingFor(new[] { typeof(MyClass) });
+			Assert.AreEqual(hbmMapping.RootClasses[0].@abstract, true);
+		}
+
 		[Test]
 		public void MapClassWithIdAndProperty()
 		{
diff --git a/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/JoinedSubclassMappingStrategyTests.cs b/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/JoinedSubclassMappingStrategyTests.cs
index f0c3ad4e570..13b259f7f37 100644
--- a/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/JoinedSubclassMappingStrategyTests.cs
+++ b/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/JoinedSubclassMappingStrategyTests.cs
@@ -79,5 +79,23 @@ public void WhenRegisteredAsJoinedSubclassThenIsEntity()
 
 			Assert.That(inspector.IsEntity(typeof(Inherited1)), Is.True);
 		}
+
+		[Test]
+		public void JoinedSubclassIsAbstract()
+		{
+			//NH-3527
+			var modelMapper = new ModelMapper();
+			modelMapper.Class<MyClass>(c => { });
+			modelMapper.JoinedSubclass<Inherited1>(c =>
+			{
+				c.Abstract(true);
+				c.Extends(typeof(MyClass));
+			});
+
+			var mappings = modelMapper.CompileMappingForAllExplicitlyAddedEntities();
+
+			Assert.IsTrue(mappings.JoinedSubclasses[0].@abstract);
+			Assert.IsTrue(mappings.JoinedSubclasses[0].extends == typeof(MyClass).FullName);
+		}
 	}
 }
\ No newline at end of file
diff --git a/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/SubclassMappingStrategyTests.cs b/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/SubclassMappingStrategyTests.cs
index 718517bac60..0fcb759b941 100644
--- a/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/SubclassMappingStrategyTests.cs
+++ b/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/SubclassMappingStrategyTests.cs
@@ -79,5 +79,23 @@ public void WhenRegisteredAsSubclassThenIsEntity()
 
 			Assert.That(inspector.IsEntity(typeof(Inherited1)), Is.True);
 		}
+
+		[Test]
+		public void SubclassIsAbstract()
+		{
+			//NH-3527
+			var modelMapper = new ModelMapper();
+			modelMapper.Class<MyClass>(c => { });
+			modelMapper.Subclass<Inherited1>(c =>
+			{
+				c.Abstract(true);
+				c.Extends(typeof(MyClass));
+			});
+
+			var mappings = modelMapper.CompileMappingForAllExplicitlyAddedEntities();
+
+			Assert.IsTrue(mappings.SubClasses[0].@abstract);
+			Assert.IsTrue(mappings.SubClasses[0].extends == typeof(MyClass).FullName);
+		}
 	}
 }
\ No newline at end of file
diff --git a/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/UnionSubclassMappingStrategyTests.cs b/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/UnionSubclassMappingStrategyTests.cs
index f72fbe1e6e7..8a8e020f005 100644
--- a/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/UnionSubclassMappingStrategyTests.cs
+++ b/src/NHibernate.Test/MappingByCode/ExplicitlyDeclaredModelTests/UnionSubclassMappingStrategyTests.cs
@@ -79,5 +79,23 @@ public void WhenRegisteredAsUnionSubclassThenIsEntity()
 
 			Assert.That(inspector.IsEntity(typeof(Inherited1)), Is.True);
 		}
+
+		[Test]
+		public void UnionSubclassIsAbstract()
+		{
+			//NH-3527
+			var modelMapper = new ModelMapper();
+			modelMapper.Class<MyClass>(c => { });
+			modelMapper.UnionSubclass<Inherited1>(c =>
+				{
+					c.Abstract(true);
+					c.Extends(typeof(MyClass));
+				});
+
+			var mappings = modelMapper.CompileMappingForAllExplicitlyAddedEntities();
+
+			Assert.IsTrue(mappings.UnionSubclasses[0].@abstract);
+			Assert.IsTrue(mappings.UnionSubclasses[0].extends == typeof(MyClass).FullName);
+		}
 	}
 }
\ No newline at end of file
diff --git a/src/NHibernate/Mapping/ByCode/IClassMapper.cs b/src/NHibernate/Mapping/ByCode/IClassMapper.cs
index b472db56cc2..5e715cf1075 100644
--- a/src/NHibernate/Mapping/ByCode/IClassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/IClassMapper.cs
@@ -13,6 +13,7 @@ public interface IClassAttributesMapper : IEntityAttributesMapper, IEntitySqlsMa
 		void ComponentAsId(MemberInfo idProperty, Action<IComponentAsIdMapper> idMapper);
 		void ComposedId(Action<IComposedIdMapper> idPropertiesMapping);
 
+		void Abstract(bool isAbstract);
 		void Discriminator(Action<IDiscriminatorMapper> discriminatorMapping);
 		void DiscriminatorValue(object value);
 		void Table(string tableName);
@@ -53,6 +54,7 @@ public interface IClassAttributesMapper<TEntity> : IEntityAttributesMapper, IEnt
 
 		void ComposedId(Action<IComposedIdMapper<TEntity>> idPropertiesMapping);
 
+		void Abstract(bool isAbstract);
 		void Discriminator(Action<IDiscriminatorMapper> discriminatorMapping);
 		void DiscriminatorValue(object value);
 		void Table(string tableName);
diff --git a/src/NHibernate/Mapping/ByCode/IJoinedSubclassMapper.cs b/src/NHibernate/Mapping/ByCode/IJoinedSubclassMapper.cs
index a68b38ec51c..1ba3e01d50b 100644
--- a/src/NHibernate/Mapping/ByCode/IJoinedSubclassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/IJoinedSubclassMapper.cs
@@ -10,13 +10,16 @@ public interface IJoinedSubclassAttributesMapper : IEntityAttributesMapper, IEnt
 		void Key(Action<IKeyMapper> keyMapping);
 		void Extends(System.Type baseType);
 		void SchemaAction(SchemaAction action);
-        void Filter(string filterName, Action<IFilterMapper> filterMapping);
+		void Filter(string filterName, Action<IFilterMapper> filterMapping);
+		void Abstract(bool isAbstract);
 	}
 
 	public interface IJoinedSubclassMapper : IJoinedSubclassAttributesMapper, IPropertyContainerMapper {}
 
 	public interface IJoinedSubclassAttributesMapper<TEntity> : IEntityAttributesMapper, IEntitySqlsMapper where TEntity : class
 	{
+		void Abstract(bool isAbstract);
+		void Extends(System.Type baseType);
 		void Table(string tableName);
 		void Catalog(string catalogName);
 		void Schema(string schemaName);
diff --git a/src/NHibernate/Mapping/ByCode/ISubclassMapper.cs b/src/NHibernate/Mapping/ByCode/ISubclassMapper.cs
index 5c6b04dc578..14a336e7a5d 100644
--- a/src/NHibernate/Mapping/ByCode/ISubclassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/ISubclassMapper.cs
@@ -7,6 +7,7 @@ public interface ISubclassAttributesMapper : IEntityAttributesMapper, IEntitySql
 		void DiscriminatorValue(object value);
 		void Extends(System.Type baseType);
 		void Filter(string filterName, Action<IFilterMapper> filterMapping);
+		void Abstract(bool isAbstract);
 	}
 
 	public interface ISubclassMapper : ISubclassAttributesMapper, IPropertyContainerMapper
@@ -18,6 +19,8 @@ public interface ISubclassAttributesMapper<TEntity> : IEntityAttributesMapper, I
 	{
 		void DiscriminatorValue(object value);
 		void Filter(string filterName, Action<IFilterMapper> filterMapping);
+		void Extends(System.Type baseType);
+		void Abstract(bool isAbstract);
 	}
 
 	public interface ISubclassMapper<TEntity> : ISubclassAttributesMapper<TEntity>, IPropertyContainerMapper<TEntity> where TEntity : class
diff --git a/src/NHibernate/Mapping/ByCode/IUnionSubclassMapper.cs b/src/NHibernate/Mapping/ByCode/IUnionSubclassMapper.cs
index 764757fefed..0ddfb9adef4 100644
--- a/src/NHibernate/Mapping/ByCode/IUnionSubclassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/IUnionSubclassMapper.cs
@@ -6,6 +6,7 @@ public interface IUnionSubclassAttributesMapper : IEntityAttributesMapper, IEnti
 		void Catalog(string catalogName);
 		void Schema(string schemaName);
 		void Extends(System.Type baseType);
+		void Abstract(bool isAbstract);
 	}
 
 	public interface IUnionSubclassMapper : IUnionSubclassAttributesMapper, IPropertyContainerMapper {}
@@ -15,6 +16,8 @@ public interface IUnionSubclassAttributesMapper<TEntity> : IEntityAttributesMapp
 		void Table(string tableName);
 		void Catalog(string catalogName);
 		void Schema(string schemaName);
+		void Extends(System.Type baseType);
+		void Abstract(bool isAbstract);
 	}
 
 	public interface IUnionSubclassMapper<TEntity> : IUnionSubclassAttributesMapper<TEntity>, IPropertyContainerMapper<TEntity> where TEntity : class {}
diff --git a/src/NHibernate/Mapping/ByCode/Impl/ClassMapper.cs b/src/NHibernate/Mapping/ByCode/Impl/ClassMapper.cs
index 2bfc5cdf439..554420f46a3 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/ClassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/ClassMapper.cs
@@ -59,6 +59,12 @@ public Dictionary<string, IJoinMapper> JoinMappers
 		}
 
 		#region Implementation of IClassMapper
+		public void Abstract(bool isAbstract)
+		{
+			classMapping.@abstract = isAbstract;
+			classMapping.abstractSpecified = true;
+		}
+
 		public void OptimisticLock(OptimisticLockMode mode)
 		{
 			classMapping.optimisticlock = (HbmOptimisticLockMode)Enum.Parse(typeof(OptimisticLockMode), mode.ToString());
diff --git a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/ClassCustomizer.cs b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/ClassCustomizer.cs
index 1393718a565..d2de6bdf921 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/ClassCustomizer.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/ClassCustomizer.cs
@@ -29,6 +29,10 @@ private Dictionary<string, IJoinMapper<TEntity>> JoinCustomizers
 		}
 
 		#region Implementation of IClassAttributesMapper<TEntity>
+		public void Abstract(bool isAbstract)
+		{
+			CustomizersHolder.AddCustomizer(typeof(TEntity), (IClassMapper m) => m.Abstract(isAbstract));
+		}
 
 		public void OptimisticLock(OptimisticLockMode mode)
 		{
diff --git a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/JoinedSubclassCustomizer.cs b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/JoinedSubclassCustomizer.cs
index 6d49e6557c4..34d74844c53 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/JoinedSubclassCustomizer.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/JoinedSubclassCustomizer.cs
@@ -111,6 +111,15 @@ public void Subselect(string sql)
 		#endregion
 
 		#region Implementation of IJoinedSubclassAttributesMapper<TEntity>
+		public void Extends(System.Type baseType)
+		{
+			CustomizersHolder.AddCustomizer(typeof(TEntity), (IJoinedSubclassAttributesMapper m) => m.Extends(baseType));
+		}
+
+		public void Abstract(bool isAbstract)
+		{
+			CustomizersHolder.AddCustomizer(typeof(TEntity), (IJoinedSubclassAttributesMapper m) => m.Abstract(isAbstract));
+		}
 
 		public void Table(string tableName)
 		{
diff --git a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/SubclassCustomizer.cs b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/SubclassCustomizer.cs
index 1b94efd7793..0f5e4ef58a0 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/SubclassCustomizer.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/SubclassCustomizer.cs
@@ -22,6 +22,15 @@ public SubclassCustomizer(IModelExplicitDeclarationsHolder explicitDeclarationsH
 		}
 
 		#region ISubclassMapper<TEntity> Members
+		public void Extends(System.Type baseType)
+		{
+			CustomizersHolder.AddCustomizer(typeof(TEntity), (ISubclassMapper m) => m.Extends(baseType));
+		}
+
+		public void Abstract(bool isAbstract)
+		{
+			CustomizersHolder.AddCustomizer(typeof(TEntity), (ISubclassMapper m) => m.Abstract(isAbstract));
+		}
 
 		public void DiscriminatorValue(object value)
 		{
diff --git a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/UnionSubclassCustomizer.cs b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/UnionSubclassCustomizer.cs
index e4c0751c1e2..6b20cdd69cb 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/UnionSubclassCustomizer.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/CustomizersImpl/UnionSubclassCustomizer.cs
@@ -97,6 +97,15 @@ public void Subselect(string sql)
 		#endregion
 
 		#region Implementation of IUnionSubclassAttributesMapper<TEntity>
+		public void Extends(System.Type baseType)
+		{
+			CustomizersHolder.AddCustomizer(typeof(TEntity), (IUnionSubclassAttributesMapper m) => m.Extends(baseType));
+		}
+
+		public void Abstract(bool isAbstract)
+		{
+			CustomizersHolder.AddCustomizer(typeof(TEntity), (IUnionSubclassAttributesMapper m) => m.Abstract(isAbstract));
+		}
 
 		public void Table(string tableName)
 		{
diff --git a/src/NHibernate/Mapping/ByCode/Impl/JoinedSubclassMapper.cs b/src/NHibernate/Mapping/ByCode/Impl/JoinedSubclassMapper.cs
index f6871711496..e096329a30a 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/JoinedSubclassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/JoinedSubclassMapper.cs
@@ -149,6 +149,11 @@ public void Subselect(string sql)
 		#endregion
 
 		#region Implementation of IJoinedSubclassAttributesMapper
+		public void Abstract(bool isAbstract)
+		{
+			classMapping.@abstract = isAbstract;
+			classMapping.abstractSpecified = true;
+		}
 
 		public void Table(string tableName)
 		{
diff --git a/src/NHibernate/Mapping/ByCode/Impl/SubclassMapper.cs b/src/NHibernate/Mapping/ByCode/Impl/SubclassMapper.cs
index c2c33c62e60..81d01caaaf0 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/SubclassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/SubclassMapper.cs
@@ -39,6 +39,11 @@ public Dictionary<string, IJoinMapper> JoinMappers
 		}
 
 		#region ISubclassMapper Members
+		public void Abstract(bool isAbstract)
+		{
+			classMapping.@abstract = isAbstract;
+			classMapping.abstractSpecified = true;
+		}
 
 		public void DiscriminatorValue(object value)
 		{
diff --git a/src/NHibernate/Mapping/ByCode/Impl/UnionSubclassMapper.cs b/src/NHibernate/Mapping/ByCode/Impl/UnionSubclassMapper.cs
index f4886ca8024..f4993bd26a0 100644
--- a/src/NHibernate/Mapping/ByCode/Impl/UnionSubclassMapper.cs
+++ b/src/NHibernate/Mapping/ByCode/Impl/UnionSubclassMapper.cs
@@ -150,6 +150,11 @@ public void Subselect(string sql)
 		#endregion
 
 		#region Implementation of IUnionSubclassAttributesMapper
+		public void Abstract(bool isAbstract)
+		{
+			classMapping.@abstract = isAbstract;
+			classMapping.abstractSpecified = true;
+		}
 
 		public void Table(string tableName)
 		{