diff --git a/Build/build.ps1 b/Build/build.ps1
index 4602aee4..100d39b4 100644
--- a/Build/build.ps1
+++ b/Build/build.ps1
@@ -19,10 +19,8 @@
     @{Name = "Newtonsoft.Json"; TestsName = "Newtonsoft.Json.Tests"; Constants=""; FinalDir="Net40"; NuGetDir = "net40"; Framework="net-4.0"; Sign=$true},
     @{Name = "Newtonsoft.Json.Portable"; TestsName = "Newtonsoft.Json.Tests.Portable"; Constants="PORTABLE"; FinalDir="Portable"; NuGetDir = "portable-net40+sl4+wp7+win8"; Framework="net-4.0"; Sign=$true},
     @{Name = "Newtonsoft.Json.WinRT"; TestsName = $null; Constants="NETFX_CORE"; FinalDir="WinRT"; NuGetDir = "winrt45"; Framework="net-4.5"; Sign=$true},
-
-    #@{Name = "Newtonsoft.Json.WindowsPhone"; TestsName = $null; Constants="SILVERLIGHT;WINDOWS_PHONE"; FinalDir="WindowsPhone"; NuGetDir = "sl3-wp,sl4-windowsphone71"; Framework="net-4.0"; Sign=$true},
+    @{Name = "Newtonsoft.Json.WindowsPhone"; TestsName = $null; Constants="SILVERLIGHT;WINDOWS_PHONE"; FinalDir="WindowsPhone"; NuGetDir = "sl3-wp,sl4-windowsphone71"; Framework="net-4.0"; Sign=$true},
     @{Name = "Newtonsoft.Json.Silverlight"; TestsName = "Newtonsoft.Json.Tests.Silverlight"; Constants="SILVERLIGHT"; FinalDir="Silverlight"; NuGetDir = "sl4"; Framework="net-4.0"; Sign=$true},
-    
     @{Name = "Newtonsoft.Json.Net35"; TestsName = "Newtonsoft.Json.Tests.Net35"; Constants="NET35"; FinalDir="Net35"; NuGetDir = "net35"; Framework="net-2.0"; Sign=$true},
     @{Name = "Newtonsoft.Json.Net20"; TestsName = "Newtonsoft.Json.Tests.Net20"; Constants="NET20"; FinalDir="Net20"; NuGetDir = "net20"; Framework="net-2.0"; Sign=$true}
   )
diff --git a/Src/Newtonsoft.Json.Tests/Newtonsoft.Json.Tests.WindowsPhone.csproj b/Src/Newtonsoft.Json.Tests/Newtonsoft.Json.Tests.WindowsPhone.csproj
index f81a8c6f..1137a275 100644
--- a/Src/Newtonsoft.Json.Tests/Newtonsoft.Json.Tests.WindowsPhone.csproj
+++ b/Src/Newtonsoft.Json.Tests/Newtonsoft.Json.Tests.WindowsPhone.csproj
@@ -102,6 +102,7 @@
     <Compile Include="Serialization\ReferenceLoopHandlingTests.cs" />
     <Compile Include="Serialization\SerializationErrorHandlingTests.cs" />
     <Compile Include="Serialization\SerializationEventAttributeTests.cs" />
+    <Compile Include="Serialization\TraceWriterTests.cs" />
     <Compile Include="Serialization\TypeNameHandlingTests.cs" />
     <Compile Include="Serialization\WebApiIntegrationTests.cs" />
     <Compile Include="TestObjects\AbstractGenericBase.cs" />
diff --git a/Src/Newtonsoft.Json/Newtonsoft.Json.WindowsPhone.csproj b/Src/Newtonsoft.Json/Newtonsoft.Json.WindowsPhone.csproj
index 5fd0d453..91566f20 100644
--- a/Src/Newtonsoft.Json/Newtonsoft.Json.WindowsPhone.csproj
+++ b/Src/Newtonsoft.Json/Newtonsoft.Json.WindowsPhone.csproj
@@ -144,6 +144,7 @@
     <Compile Include="Serialization\ErrorEventArgs.cs" />
     <Compile Include="Serialization\IContractResolver.cs" />
     <Compile Include="Serialization\IReferenceResolver.cs" />
+    <Compile Include="Serialization\ITraceWriter.cs" />
     <Compile Include="Serialization\IValueProvider.cs" />
     <Compile Include="Serialization\JsonArrayContract.cs" />
     <Compile Include="Serialization\JsonContainerContract.cs" />
@@ -167,6 +168,7 @@
     <Compile Include="Serialization\OnErrorAttribute.cs" />
     <Compile Include="Serialization\ReflectionValueProvider.cs" />
     <Compile Include="StreamingContext.cs" />
+    <Compile Include="TraceLevel.cs" />
     <Compile Include="TypeNameHandling.cs" />
     <Compile Include="Utilities\Base64Encoder.cs" />
     <Compile Include="Utilities\BidirectionalDictionary.cs" />
diff --git a/Src/Newtonsoft.Json/Utilities/ConvertUtils.cs b/Src/Newtonsoft.Json/Utilities/ConvertUtils.cs
index b30219a9..b8de27bc 100644
--- a/Src/Newtonsoft.Json/Utilities/ConvertUtils.cs
+++ b/Src/Newtonsoft.Json/Utilities/ConvertUtils.cs
@@ -332,7 +332,7 @@ namespace Newtonsoft.Json.Utilities
         if (targetType == typeof (Uri))
           return new Uri((string) initialValue, UriKind.RelativeOrAbsolute);
         if (targetType == typeof (TimeSpan))
-#if !(NET35 || NET20 || PORTABLE)
+#if !(NET35 || NET20 || PORTABLE || WINDOWS_PHONE)
           return TimeSpan.Parse((string) initialValue, CultureInfo.InvariantCulture);
 #else
           return TimeSpan.Parse((string)initialValue);