diff --git a/src/NHibernate.Test/Async/NHSpecificTest/GH3403OneToOne/Fixture.cs b/src/NHibernate.Test/Async/NHSpecificTest/GH3403OneToOne/Fixture.cs
new file mode 100644
index 00000000000..85c119e905c
--- /dev/null
+++ b/src/NHibernate.Test/Async/NHSpecificTest/GH3403OneToOne/Fixture.cs
@@ -0,0 +1,74 @@
+//------------------------------------------------------------------------------
+// <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 NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3403OneToOne
+{
+	using System.Threading.Tasks;
+	[TestFixture]
+	public class FixtureAsync : BugTestCase
+	{
+		private Guid _id;
+
+		protected override void OnSetUp()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+			var entity = new Entity1
+			{
+				Child = new Entity2()
+			};
+
+			entity.Child.Parent = entity;
+
+			session.Save(entity);
+			transaction.Commit();
+			_id = entity.Id;
+		}
+
+		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 OrphanDeleteForDetachedOneToOneAsync()
+		{
+			Guid childId;
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var entity = await (session.GetAsync<Entity1>(_id));
+				childId = entity.Child.Id;
+				await (session.EvictAsync(entity.Child));
+				entity.Child = null;
+
+				await (session.FlushAsync());
+				await (transaction.CommitAsync());
+			}
+
+			using (var session = OpenSession())
+			{
+				var entity = await (session.GetAsync<Entity1>(_id));
+				Assert.That(entity, Is.Not.Null);
+				Assert.That(entity.Child, Is.Null, "Unexpected child on parent");
+
+				var child = await (session.GetAsync<Entity2>(childId));
+				Assert.That(child , Is.Null, "Child is still in database");
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Entity.cs b/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Entity.cs
new file mode 100644
index 00000000000..0bde7420b92
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Entity.cs
@@ -0,0 +1,17 @@
+using System;
+
+namespace NHibernate.Test.NHSpecificTest.GH3403OneToOne
+{
+	public class Entity1
+	{
+		public virtual Guid Id { get; set; }
+
+		public virtual Entity2 Child { get; set; }
+	}
+	public class Entity2
+	{
+		public virtual Guid Id { get; set; }
+
+		public virtual Entity1 Parent { get; set; }
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Fixture.cs b/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Fixture.cs
new file mode 100644
index 00000000000..08f965eef1d
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Fixture.cs
@@ -0,0 +1,63 @@
+using System;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3403OneToOne
+{
+	[TestFixture]
+	public class Fixture : BugTestCase
+	{
+		private Guid _id;
+
+		protected override void OnSetUp()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+			var entity = new Entity1
+			{
+				Child = new Entity2()
+			};
+
+			entity.Child.Parent = entity;
+
+			session.Save(entity);
+			transaction.Commit();
+			_id = entity.Id;
+		}
+
+		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 OrphanDeleteForDetachedOneToOne()
+		{
+			Guid childId;
+			using (var session = OpenSession())
+			using (var transaction = session.BeginTransaction())
+			{
+				var entity = session.Get<Entity1>(_id);
+				childId = entity.Child.Id;
+				session.Evict(entity.Child);
+				entity.Child = null;
+
+				session.Flush();
+				transaction.Commit();
+			}
+
+			using (var session = OpenSession())
+			{
+				var entity = session.Get<Entity1>(_id);
+				Assert.That(entity, Is.Not.Null);
+				Assert.That(entity.Child, Is.Null, "Unexpected child on parent");
+
+				var child = session.Get<Entity2>(childId);
+				Assert.That(child , Is.Null, "Child is still in database");
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Mappings.hbm.xml b/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Mappings.hbm.xml
new file mode 100644
index 00000000000..175d587c0ce
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH3403OneToOne/Mappings.hbm.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="NHibernate.Test"
+                   namespace="NHibernate.Test.NHSpecificTest.GH3403OneToOne">
+  <class name="Entity1">
+    <id name="Id">
+      <generator class="guid"/>
+    </id>
+    <one-to-one name="Child" cascade="all-delete-orphan" foreign-key="none" />
+  </class>
+  <class name="Entity2">
+    <id name="Id">
+      <generator class="foreign">
+        <param name="property">Parent</param>
+      </generator>
+    </id>
+    <one-to-one name="Parent" foreign-key="none"  />
+  </class>
+</hibernate-mapping>
diff --git a/src/NHibernate/Async/Engine/Cascade.cs b/src/NHibernate/Async/Engine/Cascade.cs
index c0165e5cf66..46877a36ae1 100644
--- a/src/NHibernate/Async/Engine/Cascade.cs
+++ b/src/NHibernate/Async/Engine/Cascade.cs
@@ -151,7 +151,7 @@ private async Task CascadePropertyAsync(object parent, object child, IType type,
 
 							if (loadedValue != null)
 							{
-								await (eventSource.DeleteAsync(entry.Persister.EntityName, loadedValue, false, null, cancellationToken)).ConfigureAwait(false);
+								await (eventSource.DeleteAsync(((EntityType) type).GetAssociatedEntityName(), loadedValue, false, null, cancellationToken)).ConfigureAwait(false);
 							}
 						}
 					}
diff --git a/src/NHibernate/Engine/Cascade.cs b/src/NHibernate/Engine/Cascade.cs
index 2c2c2987a3b..35098331337 100644
--- a/src/NHibernate/Engine/Cascade.cs
+++ b/src/NHibernate/Engine/Cascade.cs
@@ -203,7 +203,7 @@ private void CascadeProperty(object parent, object child, IType type, CascadeSty
 
 							if (loadedValue != null)
 							{
-								eventSource.Delete(entry.Persister.EntityName, loadedValue, false, null);
+								eventSource.Delete(((EntityType) type).GetAssociatedEntityName(), loadedValue, false, null);
 							}
 						}
 					}