diff --git a/src/Umbraco.Core/Components/Composition.cs b/src/Umbraco.Core/Components/Composition.cs
index cc52b2d814..53acbdb132 100644
--- a/src/Umbraco.Core/Components/Composition.cs
+++ b/src/Umbraco.Core/Components/Composition.cs
@@ -89,7 +89,10 @@ namespace Umbraco.Core.Components
                 onCreating();
 
             foreach (var unique in _uniques.Values)
-                unique.RegisterTo(_register);
+                unique.RegisterWith(_register);
+
+            foreach (var builder in _builders.Values)
+                builder.RegisterWith(_register);
 
             return _register.CreateFactory();
         }
@@ -147,7 +150,7 @@ namespace Umbraco.Core.Components
                 _instance = instance;
             }
 
-            public virtual void RegisterTo(IRegister register)
+            public virtual void RegisterWith(IRegister register)
             {
                 if (_implementingType != null)
                     register.Register(_serviceType, _implementingType, Lifetime.Singleton);
@@ -166,7 +169,7 @@ namespace Umbraco.Core.Components
                 _factory = factory;
             }
 
-            public override void RegisterTo(IRegister register)
+            public override void RegisterWith(IRegister register)
             {
                 register.Register(_factory, Lifetime.Singleton);
             }
@@ -190,10 +193,7 @@ namespace Umbraco.Core.Components
                 return (TBuilder) o;
 
             var builder = new TBuilder();
-            builder.Initialize(_register);
-
             _builders[typeOfBuilder] = builder;
-
             return builder;
         }
 
diff --git a/src/Umbraco.Core/Composing/CollectionBuilderBase.cs b/src/Umbraco.Core/Composing/CollectionBuilderBase.cs
index f370e9bd8c..7633f6b001 100644
--- a/src/Umbraco.Core/Composing/CollectionBuilderBase.cs
+++ b/src/Umbraco.Core/Composing/CollectionBuilderBase.cs
@@ -18,29 +18,22 @@ namespace Umbraco.Core.Composing
         private readonly object _locker = new object();
         private Type[] _registeredTypes;
 
-        /// <summary>
-        /// Gets the container.
-        /// </summary>
-        protected IRegister Container { get; private set; }
-
         /// <summary>
         /// Gets the internal list of types as an IEnumerable (immutable).
         /// </summary>
         public IEnumerable<Type> GetTypes() => _types;
 
-        /// <summary>
-        /// Initializes a new instance of the builder.
-        /// </summary>
-        /// <remarks>By default, this registers the collection automatically.</remarks>
-        public virtual void Initialize(IRegister container)
+        /// <inheritdoc />
+        public virtual void RegisterWith(IRegister register)
         {
-            if (Container != null)
-                throw new InvalidOperationException("This builder has already been initialized.");
-
-            Container = container;
+            if (_registeredTypes != null)
+                throw new InvalidOperationException("This builder has already been registered.");
 
             // register the collection
-            Container.Register(CreateCollection, CollectionLifetime);
+            register.Register(CreateCollection, CollectionLifetime);
+
+            // register the types
+            RegisterTypes(register);
         }
 
         /// <summary>
@@ -58,7 +51,7 @@ namespace Umbraco.Core.Composing
             lock (_locker)
             {
                 if (_registeredTypes != null)
-                    throw new InvalidOperationException("Cannot configure a collection builder after its types have been resolved.");
+                    throw new InvalidOperationException("Cannot configure a collection builder after it has been registered.");
                 action(_types);
             }
         }
@@ -74,7 +67,7 @@ namespace Umbraco.Core.Composing
             return types;
         }
 
-        private void RegisterTypes()
+        private void RegisterTypes(IRegister register)
         {
             lock (_locker)
             {
@@ -88,7 +81,7 @@ namespace Umbraco.Core.Composing
 
                 // register them
                 foreach (var type in types)
-                    Container.Register(type);
+                    register.Register(type);
 
                 _registeredTypes = types;
             }
@@ -100,7 +93,8 @@ namespace Umbraco.Core.Composing
         /// <returns>The collection items.</returns>
         protected virtual IEnumerable<TItem> CreateItems(IFactory factory)
         {
-            RegisterTypes(); // will do it only once
+            if (_registeredTypes == null)
+                throw new InvalidOperationException("Cannot create items before the collection builder has been registered.");
 
             return _registeredTypes // respect order
                 .Select(x => CreateItem(factory, x))
diff --git a/src/Umbraco.Core/Composing/ICollectionBuilder.cs b/src/Umbraco.Core/Composing/ICollectionBuilder.cs
index e17a362e6d..84ff3ba747 100644
--- a/src/Umbraco.Core/Composing/ICollectionBuilder.cs
+++ b/src/Umbraco.Core/Composing/ICollectionBuilder.cs
@@ -6,9 +6,10 @@
     public interface ICollectionBuilder
     {
         /// <summary>
-        /// Initializes a new instance of the builder, and registers the collection.
+        /// Registers the builder so it can build the collection, by
+        /// registering the collection and the types.
         /// </summary>
-        void Initialize(IRegister container);
+        void RegisterWith(IRegister register);
     }
 
     /// <summary>
diff --git a/src/Umbraco.Core/Persistence/Mappers/MapperCollectionBuilder.cs b/src/Umbraco.Core/Persistence/Mappers/MapperCollectionBuilder.cs
index 40bc76928b..80819933f5 100644
--- a/src/Umbraco.Core/Persistence/Mappers/MapperCollectionBuilder.cs
+++ b/src/Umbraco.Core/Persistence/Mappers/MapperCollectionBuilder.cs
@@ -6,9 +6,9 @@ namespace Umbraco.Core.Persistence.Mappers
     {
         protected override MapperCollectionBuilder This => this;
 
-        public override void Initialize(IRegister container)
+        public override void RegisterWith(IRegister register)
         {
-            base.Initialize(container);
+            base.RegisterWith(register);
 
             // default initializer registers
             // - service MapperCollectionBuilder, returns MapperCollectionBuilder
@@ -16,7 +16,7 @@ namespace Umbraco.Core.Persistence.Mappers
             // we want to register extra
             // - service IMapperCollection, returns MappersCollectionBuilder's collection
 
-            Container.Register<IMapperCollection>(factory => factory.GetInstance<MapperCollection>());
+            register.Register<IMapperCollection>(factory => factory.GetInstance<MapperCollection>());
         }
 
         public MapperCollectionBuilder AddCoreMappers()
diff --git a/src/Umbraco.Tests/Components/ComponentTests.cs b/src/Umbraco.Tests/Components/ComponentTests.cs
index f50feb1d00..6836ca433c 100644
--- a/src/Umbraco.Tests/Components/ComponentTests.cs
+++ b/src/Umbraco.Tests/Components/ComponentTests.cs
@@ -184,7 +184,9 @@ namespace Umbraco.Tests.Components
             Composed.Clear();
             Initialized.Clear();
             composers.Compose();
-            var components = composition.WithCollectionBuilder<ComponentCollectionBuilder>().CreateCollection(factory);
+            var builder = composition.WithCollectionBuilder<ComponentCollectionBuilder>();
+            builder.RegisterWith(register);
+            var components = builder.CreateCollection(factory);
             Assert.AreEqual(2, Composed.Count);
             Assert.AreEqual(typeof(Composer1), Composed[0]);
             Assert.AreEqual(typeof(Composer5), Composed[1]);
@@ -234,7 +236,9 @@ namespace Umbraco.Tests.Components
             var composers = new Composers(composition, types, Mock.Of<IProfilingLogger>());
             Composed.Clear();
             composers.Compose();
-            var components = composition.WithCollectionBuilder<ComponentCollectionBuilder>().CreateCollection(factory);
+            var builder = composition.WithCollectionBuilder<ComponentCollectionBuilder>();
+            builder.RegisterWith(register);
+            var components = builder.CreateCollection(factory);
             Assert.AreEqual(3, Composed.Count);
             Assert.AreEqual(typeof(Composer4), Composed[0]);
             Assert.AreEqual(typeof(Composer2), Composed[1]);
diff --git a/src/Umbraco.Tests/Composing/LazyCollectionBuilderTests.cs b/src/Umbraco.Tests/Composing/LazyCollectionBuilderTests.cs
index b9edb96f1c..cbabae1a83 100644
--- a/src/Umbraco.Tests/Composing/LazyCollectionBuilderTests.cs
+++ b/src/Umbraco.Tests/Composing/LazyCollectionBuilderTests.cs
@@ -129,12 +129,10 @@ namespace Umbraco.Tests.Composing
                 // legal so far...
                 .Add(() => new[] { typeof(TransientObject4)  });
 
-            var factory = composition.CreateFactory();
-
             Assert.Throws<InvalidOperationException>(() =>
             {
-                // but throws here when trying to register the types
-                var values = factory.GetInstance<TestCollection>();
+                // but throws here when trying to register the types, right before creating the factory
+                var factory = composition.CreateFactory();
             });
         }
 
diff --git a/src/Umbraco.Tests/TestHelpers/BaseUsingSqlCeSyntax.cs b/src/Umbraco.Tests/TestHelpers/BaseUsingSqlCeSyntax.cs
index 9ba8c6fb83..7fd2f0f18b 100644
--- a/src/Umbraco.Tests/TestHelpers/BaseUsingSqlCeSyntax.cs
+++ b/src/Umbraco.Tests/TestHelpers/BaseUsingSqlCeSyntax.cs
@@ -37,20 +37,21 @@ namespace Umbraco.Tests.TestHelpers
 
             var container = RegisterFactory.Create();
 
-            var composition = new Composition(container, new TypeLoader(), Mock.Of<IProfilingLogger>(), ComponentTests.MockRuntimeState(RuntimeLevel.Run));
+            var logger = new ProfilingLogger(Mock.Of<ILogger>(), Mock.Of<IProfiler>());
+            var typeLoader = new TypeLoader(NullCacheProvider.Instance,
+                LocalTempStorage.Default,
+                logger,
+                false);
+
+            var composition = new Composition(container, typeLoader, Mock.Of<IProfilingLogger>(), ComponentTests.MockRuntimeState(RuntimeLevel.Run));
 
             composition.RegisterUnique<ILogger>(_ => Mock.Of<ILogger>());
             composition.RegisterUnique<IProfiler>(_ => Mock.Of<IProfiler>());
 
-            var logger = new ProfilingLogger(Mock.Of<ILogger>(), Mock.Of<IProfiler>());
-            var pluginManager = new TypeLoader(NullCacheProvider.Instance,
-                LocalTempStorage.Default,
-                logger,
-                false);
-            composition.RegisterUnique(pluginManager);
+            composition.RegisterUnique(typeLoader);
 
             composition.WithCollectionBuilder<MapperCollectionBuilder>()
-                .Add(() => Current.TypeLoader.GetAssignedMapperTypes());
+                .Add(() => composition.TypeLoader.GetAssignedMapperTypes());
 
             var factory = Current.Factory = composition.CreateFactory();
 
diff --git a/src/Umbraco.Web/Runtime/WebRuntimeComponent.cs b/src/Umbraco.Web/Runtime/WebRuntimeComponent.cs
index 4d31c4a351..8aff0457ea 100644
--- a/src/Umbraco.Web/Runtime/WebRuntimeComponent.cs
+++ b/src/Umbraco.Web/Runtime/WebRuntimeComponent.cs
@@ -32,7 +32,7 @@ using Current = Umbraco.Web.Composing.Current;
 
 namespace Umbraco.Web.Runtime
 {
-    internal sealed class WebRuntimeComponent : IComponent
+    public sealed class WebRuntimeComponent : IComponent
     {
         public WebRuntimeComponent(
             IRuntimeState runtime,