diff --git a/src/Umbraco.Core/Persistence/UnitOfWork/FileUnitOfWork.cs b/src/Umbraco.Core/Persistence/UnitOfWork/FileUnitOfWork.cs
index d7562e716f..7a0fe55fda 100644
--- a/src/Umbraco.Core/Persistence/UnitOfWork/FileUnitOfWork.cs
+++ b/src/Umbraco.Core/Persistence/UnitOfWork/FileUnitOfWork.cs
@@ -8,17 +8,14 @@
     /// mechanism.</remarks>
     internal class FileUnitOfWork : UnitOfWorkBase
     {
-        private readonly RepositoryFactory _factory;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="NPocoUnitOfWork"/> class with a a repository factory.
         /// </summary>
         /// <param name="factory">A repository factory.</param>
         /// <remarks>This should be used by the FileUnitOfWorkProvider exclusively.</remarks>
         public FileUnitOfWork(RepositoryFactory factory)
-        {
-            _factory = factory;
-        }
+            : base(factory)
+        { }
 
         /// <summary>
         /// Creates a repository.
@@ -28,7 +25,7 @@
         /// <returns>The created repository for the unit of work.</returns>
 	    public override TRepository CreateRepository<TRepository>(string name = null)
         {
-            return _factory.CreateRepository<TRepository>(this, name);
+            return Factory.CreateRepository<TRepository>(this, name);
         }
     }
 }
\ No newline at end of file
diff --git a/src/Umbraco.Core/Persistence/UnitOfWork/IUnitOfWork.cs b/src/Umbraco.Core/Persistence/UnitOfWork/IUnitOfWork.cs
index a3ec517546..0f8d775020 100644
--- a/src/Umbraco.Core/Persistence/UnitOfWork/IUnitOfWork.cs
+++ b/src/Umbraco.Core/Persistence/UnitOfWork/IUnitOfWork.cs
@@ -33,7 +33,7 @@ namespace Umbraco.Core.Persistence.UnitOfWork
         /// <summary>
         /// Begins the unit of work.
         /// </summary>
-        /// <remarks>When a unit of work begins, a local transaction scope is created at database level. 
+        /// <remarks>When a unit of work begins, a local transaction scope is created at database level.
         /// This is useful eg when reading entities before creating, updating or deleting, and the read
         /// needs to be part of the transaction. Flushing or completing the unit of work automatically
         /// begins the transaction (so no need to call Begin if not necessary).</remarks>
@@ -58,8 +58,11 @@ namespace Umbraco.Core.Persistence.UnitOfWork
         /// before it is disposed, all queued operations are cleared and the scope is rolled back (and also
         /// higher level transactions if any).
         /// Whether this actually commits or rolls back the transaction depends on whether the transaction scope
-        /// is part of a higher level transactions. The  database transaction is committed or rolled back only 
+        /// is part of a higher level transactions. The  database transaction is committed or rolled back only
         /// when the upper level scope is disposed.
+        /// If any operation is added to the unit of work after it has been completed, then its completion
+        /// status is resetted. So in a way it could be possible to always complete and never flush, but flush
+        /// is preferred when appropriate to indicate that you understand what you are doing.
         /// </remarks>
         void Complete();
 
diff --git a/src/Umbraco.Core/Persistence/UnitOfWork/NPocoUnitOfWork.cs b/src/Umbraco.Core/Persistence/UnitOfWork/NPocoUnitOfWork.cs
index 8e68f9ade3..08550c2b76 100644
--- a/src/Umbraco.Core/Persistence/UnitOfWork/NPocoUnitOfWork.cs
+++ b/src/Umbraco.Core/Persistence/UnitOfWork/NPocoUnitOfWork.cs
@@ -9,7 +9,6 @@ namespace Umbraco.Core.Persistence.UnitOfWork
     /// </summary>
     internal class NPocoUnitOfWork : UnitOfWorkBase, IDatabaseUnitOfWork
     {
-        private readonly RepositoryFactory _factory;
         private ITransaction _transaction;
 
         /// <summary>
@@ -19,9 +18,9 @@ namespace Umbraco.Core.Persistence.UnitOfWork
         /// <param name="factory">A repository factory.</param>
         /// <remarks>This should be used by the NPocoUnitOfWorkProvider exclusively.</remarks>
         internal NPocoUnitOfWork(UmbracoDatabase database, RepositoryFactory factory)
+            : base(factory)
         {
             Database = database;
-            _factory = factory;
         }
 
         /// <summary>
@@ -37,7 +36,7 @@ namespace Umbraco.Core.Persistence.UnitOfWork
         /// <returns>The created repository for the unit of work.</returns>
         public override TRepository CreateRepository<TRepository>(string name = null)
         {
-            return _factory.CreateRepository<TRepository>(this, name);
+            return Factory.CreateRepository<TRepository>(this, name);
         }
 
         /// <summary>
diff --git a/src/Umbraco.Core/Persistence/UnitOfWork/UnitOfWorkBase.cs b/src/Umbraco.Core/Persistence/UnitOfWork/UnitOfWorkBase.cs
index 16fd84aa73..98fd1fa6d8 100644
--- a/src/Umbraco.Core/Persistence/UnitOfWork/UnitOfWorkBase.cs
+++ b/src/Umbraco.Core/Persistence/UnitOfWork/UnitOfWorkBase.cs
@@ -9,8 +9,15 @@ namespace Umbraco.Core.Persistence.UnitOfWork
     {
         private readonly Queue<Operation> _operations = new Queue<Operation>();
 
-        // fixme eventually kill this
-        public virtual T CreateRepository<T>(string name = null) where T:IRepository {  throw new NotImplementedException(); }
+        protected UnitOfWorkBase(RepositoryFactory factory)
+        {
+            Factory = factory;
+        }
+
+        protected RepositoryFactory Factory { get; }
+
+        public abstract TRepository CreateRepository<TRepository>(string name = null)
+            where TRepository : IRepository;
 
         /// <summary>
         /// Registers an entity to be added as part of this unit of work.