diff --git a/.gitmodules b/.gitmodules
index bdd5d5ca4d..6e9b10efa4 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,4 +7,4 @@
 	branch = perspex-pcl
 [submodule "src/Markup/Avalonia.Markup.Xaml/PortableXaml/portable.xaml.github"]
 	path = src/Markup/Avalonia.Markup.Xaml/PortableXaml/portable.xaml.github
-	url = https://github.com/cwensley/Portable.Xaml.git
+	url = https://github.com/AvaloniaUI/Portable.Xaml.git
diff --git a/build/Markup.props b/build/Markup.props
index 0e4baf5da9..5be0cfbf0c 100644
--- a/build/Markup.props
+++ b/build/Markup.props
@@ -9,5 +9,6 @@
     <PackageReference Include="System.ComponentModel.Primitives" Version="4.3.0" />
     <PackageReference Include="System.Runtime.Serialization.Primitives" Version="4.3.0" />
     <PackageReference Include="System.Xml.XmlDocument" Version="4.3.0" />
+    <PackageReference Include="System.Xml.ReaderWriter" Version="4.3.0" />
   </ItemGroup>
 </Project>
diff --git a/packages.cake b/packages.cake
index 5f268188dc..1f37461da7 100644
--- a/packages.cake
+++ b/packages.cake
@@ -248,7 +248,7 @@ public class Packages
                 }
                 .Deps(new string[]{null, "netcoreapp1.0"},
                     "System.ValueTuple", "System.ComponentModel.TypeConverter", "System.ComponentModel.Primitives",
-                    "System.Runtime.Serialization.Primitives", "System.Xml.XmlDocument")
+                    "System.Runtime.Serialization.Primitives", "System.Xml.XmlDocument", "System.Xml.ReaderWriter")
                 .ToArray(),
                 Files = coreLibrariesNuSpecContent
                     .Concat(win32CoreLibrariesNuSpecContent).Concat(net45RuntimePlatform)
diff --git a/src/Markup/Avalonia.Markup.Xaml/AvaloniaXamlLoaderPortableXaml.cs b/src/Markup/Avalonia.Markup.Xaml/AvaloniaXamlLoaderPortableXaml.cs
index c49797f2f8..0419db5d0f 100644
--- a/src/Markup/Avalonia.Markup.Xaml/AvaloniaXamlLoaderPortableXaml.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/AvaloniaXamlLoaderPortableXaml.cs
@@ -189,7 +189,7 @@ namespace Avalonia.Markup.Xaml
                                     context);
 
             XamlServices.Transform(reader, writer);
-
+            writer.ApplyAllDelayedProperties();
             return writer.Result;
         }
 
diff --git a/src/Markup/Avalonia.Markup.Xaml/Converters/SetterValueTypeConverter.cs b/src/Markup/Avalonia.Markup.Xaml/Converters/SetterValueTypeConverter.cs
index 931d4e2ffc..81cda6db1f 100644
--- a/src/Markup/Avalonia.Markup.Xaml/Converters/SetterValueTypeConverter.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/Converters/SetterValueTypeConverter.cs
@@ -23,11 +23,11 @@ namespace Avalonia.Markup.Xaml.Converters
             object setter = context.GetService<IProvideValueTarget>().TargetObject;
             var schemaContext = context.GetService<IXamlSchemaContextProvider>().SchemaContext;
 
-            return ConvertSetterValue(schemaContext, (setter as Setter), value);
+            return ConvertSetterValue(context, schemaContext, culture, (setter as Setter), value);
         }
 
         [Obsolete("TODO: try assosiate Setter.Value property with SetterValueTypeConverter, so far coouldn't make it :(")]
-        internal static object ConvertSetterValue(XamlSchemaContext context, Setter setter, object value)
+        internal static object ConvertSetterValue(ITypeDescriptorContext dcontext, XamlSchemaContext context, CultureInfo info, Setter setter, object value)
         {
             Type targetType = setter?.Property?.PropertyType;
 
@@ -40,7 +40,7 @@ namespace Avalonia.Markup.Xaml.Converters
 
             if (ttConv != null)
             {
-                value = ttConv.ConvertFromString(value as string);
+                value = ttConv.ConvertFromString(dcontext, info, value as string);
             }
 
             return value;
diff --git a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs
index f10de1a32f..e0e2553f46 100644
--- a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlObjectWriter.cs
@@ -54,6 +54,12 @@ namespace Avalonia.Markup.Xaml.PortableXaml
             base.Dispose(disposing);
         }
 
+        public void ApplyAllDelayedProperties()
+        {
+            //HACK: We need this because Begin/EndInit ordering is broken
+            _delayedValuesHelper.ApplyAll();
+        }
+
         protected internal override void OnAfterBeginInit(object value)
         {
             //not called for avalonia objects
@@ -88,8 +94,8 @@ namespace Avalonia.Markup.Xaml.PortableXaml
             //Portable.Xaml.ComponentModel.ISupportInitialize
             //and we have Avalonia.ISupportInitialize so we need some hacks
             HandleBeginInit(value);
-
-            _delayedValuesHelper.BeginInit(value);
+            if (value != null)
+                _delayedValuesHelper.BeginInit(value);
 
             base.OnBeforeProperties(value);
         }
@@ -137,7 +143,7 @@ namespace Avalonia.Markup.Xaml.PortableXaml
 
                 if (_cnt == 0)
                 {
-                    EndInit();
+                    ApplyAll();
                 }
             }
 
@@ -174,7 +180,7 @@ namespace Avalonia.Markup.Xaml.PortableXaml
                 }
             }
 
-            private void EndInit()
+            public void ApplyAll()
             {
                 //TODO: revisit this
                 //apply delayed values and clear
diff --git a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlType.cs b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlType.cs
index 8fcde185b3..71c8902cbd 100644
--- a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlType.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/AvaloniaXamlType.cs
@@ -8,6 +8,7 @@ using Portable.Xaml.Schema;
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Reflection;
 using System.Xml.Serialization;
 
@@ -203,8 +204,8 @@ namespace Avalonia.Markup.Xaml.PortableXaml
                     Member.Name == nameof(Setter.Value) &&
                     value is string)
                 {
-                    value = SetterValueTypeConverter.ConvertSetterValue(
-                                            Member.DeclaringType.SchemaContext,
+                    value = SetterValueTypeConverter.ConvertSetterValue(null,
+                                            Member.DeclaringType.SchemaContext, CultureInfo.InvariantCulture,
                                             instance as Setter,
                                             value);
                 }
@@ -331,7 +332,7 @@ namespace Avalonia.Markup.Xaml.PortableXaml
 
             public override object GetValue(object instance)
             {
-                if (Property != null)
+                if (Property != null && !Property.IsAttached)
                 {
                     return ((IAvaloniaObject)instance).GetValue(Property);
                 }
diff --git a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/portable.xaml.github b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/portable.xaml.github
index d50730ab59..dfc5affa5d 160000
--- a/src/Markup/Avalonia.Markup.Xaml/PortableXaml/portable.xaml.github
+++ b/src/Markup/Avalonia.Markup.Xaml/PortableXaml/portable.xaml.github
@@ -1 +1 @@
-Subproject commit d50730ab59aed99cd2f8aeb4975fcc19d23bb54f
+Subproject commit dfc5affa5d8f4ddf5a7707e3202d5593519de640