diff --git a/Build/build.ps1 b/Build/build.ps1
index aeeee77e..344f52c1 100644
--- a/Build/build.ps1
+++ b/Build/build.ps1
@@ -11,6 +11,7 @@
   $buildNuGet = $true
   $treatWarningsAsErrors = $false
   $workingName = if ($workingName) {$workingName} else {"Working"}
+  $dnvmVersion = "1.0.0-beta8-15530"
   
   $baseDir  = resolve-path ..
   $buildDir = "$baseDir\Build"
@@ -93,7 +94,7 @@ task Package -depends Build {
     if ($nugetPrelease -ne $null)
     {
       $nugetVersion = $nugetVersion + "-" + $nugetPrelease
-    }    
+    }
 
     New-Item -Path $workingDir\NuGet -ItemType Directory
 
@@ -210,8 +211,8 @@ function DnxBuild($build)
 {
   $name = $build.Name
 
-  exec { dnvm install 1.0.0-beta8-15120 -r clr -u | Out-Default }
-  exec { dnvm use 1.0.0-beta8-15120 -r clr | Out-Default }
+  exec { dnvm install $dnvmVersion -r clr -u | Out-Default }
+  exec { dnvm use $dnvmVersion -r clr | Out-Default }
 
   Write-Host -ForegroundColor Green "Restoring packages for $name"
   Write-Host
@@ -240,8 +241,8 @@ function DnxTests($build)
   #Write-Host
   #exec { & $toolsDir\Kvm\kvm.ps1 upgrade -r CoreCLR -NoNative | Out-Default }
 
-  exec { dnvm install 1.0.0-beta8-15120 -r coreclr -u | Out-Default }
-  exec { dnvm use 1.0.0-beta8-15120 -r coreclr | Out-Default }
+  exec { dnvm install $dnvmVersion -r coreclr -u | Out-Default }
+  exec { dnvm use $dnvmVersion -r coreclr | Out-Default }
 
   Write-Host -ForegroundColor Green "Restoring packages for $name"
   Write-Host
diff --git a/Src/Newtonsoft.Json/Linq/JContainer.cs b/Src/Newtonsoft.Json/Linq/JContainer.cs
index a705b577..f99d88d3 100644
--- a/Src/Newtonsoft.Json/Linq/JContainer.cs
+++ b/Src/Newtonsoft.Json/Linq/JContainer.cs
@@ -227,7 +227,11 @@ namespace Newtonsoft.Json.Linq
         /// </value>
         public override JToken First
         {
-            get { return ChildrenTokens.FirstOrDefault(); }
+            get
+            {
+                IList<JToken> children = ChildrenTokens;
+                return (children.Count > 0) ? children[0] : null;
+            }
         }
 
         /// <summary>
@@ -238,7 +242,12 @@ namespace Newtonsoft.Json.Linq
         /// </value>
         public override JToken Last
         {
-            get { return ChildrenTokens.LastOrDefault(); }
+            get
+            {
+                IList<JToken> children = ChildrenTokens;
+                int count = children.Count;
+                return (count > 0) ? children[count - 1] : null;
+            }
         }
 
         /// <summary>
@@ -349,16 +358,18 @@ namespace Newtonsoft.Json.Linq
 
         internal virtual void InsertItem(int index, JToken item, bool skipParentCheck)
         {
-            if (index > ChildrenTokens.Count)
+            IList<JToken> children = ChildrenTokens;
+
+            if (index > children.Count)
                 throw new ArgumentOutOfRangeException("index", "Index must be within the bounds of the List.");
 
             CheckReentrancy();
 
             item = EnsureParentToken(item, skipParentCheck);
 
-            JToken previous = (index == 0) ? null : ChildrenTokens[index - 1];
+            JToken previous = (index == 0) ? null : children[index - 1];
             // haven't inserted new token yet so next token is still at the inserting index
-            JToken next = (index == ChildrenTokens.Count) ? null : ChildrenTokens[index];
+            JToken next = (index == children.Count) ? null : children[index];
 
             ValidateToken(item, null);
 
@@ -372,7 +383,7 @@ namespace Newtonsoft.Json.Linq
             if (next != null)
                 next.Previous = item;
 
-            ChildrenTokens.Insert(index, item);
+            children.Insert(index, item);
 
 #if !(DOTNET || PORTABLE40 || PORTABLE)
             if (_listChanged != null)
@@ -386,16 +397,18 @@ namespace Newtonsoft.Json.Linq
 
         internal virtual void RemoveItemAt(int index)
         {
+            IList<JToken> children = ChildrenTokens;
+
             if (index < 0)
                 throw new ArgumentOutOfRangeException("index", "Index is less than 0.");
-            if (index >= ChildrenTokens.Count)
+            if (index >= children.Count)
                 throw new ArgumentOutOfRangeException("index", "Index is equal to or greater than Count.");
 
             CheckReentrancy();
 
-            JToken item = ChildrenTokens[index];
-            JToken previous = (index == 0) ? null : ChildrenTokens[index - 1];
-            JToken next = (index == ChildrenTokens.Count - 1) ? null : ChildrenTokens[index + 1];
+            JToken item = children[index];
+            JToken previous = (index == 0) ? null : children[index - 1];
+            JToken next = (index == children.Count - 1) ? null : children[index + 1];
 
             if (previous != null)
                 previous.Next = next;
@@ -406,7 +419,7 @@ namespace Newtonsoft.Json.Linq
             item.Previous = null;
             item.Next = null;
 
-            ChildrenTokens.RemoveAt(index);
+            children.RemoveAt(index);
 
 #if !(DOTNET || PORTABLE40 || PORTABLE)
             if (_listChanged != null)
@@ -437,12 +450,14 @@ namespace Newtonsoft.Json.Linq
 
         internal virtual void SetItem(int index, JToken item)
         {
+            IList<JToken> children = ChildrenTokens;
+
             if (index < 0)
                 throw new ArgumentOutOfRangeException("index", "Index is less than 0.");
-            if (index >= ChildrenTokens.Count)
+            if (index >= children.Count)
                 throw new ArgumentOutOfRangeException("index", "Index is equal to or greater than Count.");
 
-            JToken existing = ChildrenTokens[index];
+            JToken existing = children[index];
 
             if (IsTokenUnchanged(existing, item))
                 return;
@@ -453,8 +468,8 @@ namespace Newtonsoft.Json.Linq
 
             ValidateToken(item, existing);
 
-            JToken previous = (index == 0) ? null : ChildrenTokens[index - 1];
-            JToken next = (index == ChildrenTokens.Count - 1) ? null : ChildrenTokens[index + 1];
+            JToken previous = (index == 0) ? null : children[index - 1];
+            JToken next = (index == children.Count - 1) ? null : children[index + 1];
 
             item.Parent = this;
 
@@ -466,7 +481,7 @@ namespace Newtonsoft.Json.Linq
             if (next != null)
                 next.Previous = item;
 
-            ChildrenTokens[index] = item;
+            children[index] = item;
 
             existing.Parent = null;
             existing.Previous = null;
@@ -486,14 +501,16 @@ namespace Newtonsoft.Json.Linq
         {
             CheckReentrancy();
 
-            foreach (JToken item in ChildrenTokens)
+            IList<JToken> children = ChildrenTokens;
+
+            foreach (JToken item in children)
             {
                 item.Parent = null;
                 item.Previous = null;
                 item.Next = null;
             }
 
-            ChildrenTokens.Clear();
+            children.Clear();
 
 #if !(DOTNET || PORTABLE40 || PORTABLE)
             if (_listChanged != null)
diff --git a/Src/NuGet.Config b/Src/NuGet.Config
index 83b1a4ed..3da0c229 100644
--- a/Src/NuGet.Config
+++ b/Src/NuGet.Config
@@ -3,9 +3,9 @@
   <packageSources>
     <!--To inherit the global NuGet package sources remove the <clear/> line below -->
     <clear />
-    <add key="CI Builds (aspnetvnext)" value="https://www.myget.org/F/aspnetvnext/" />
-    <add key="CI Builds (xunit)" value="https://www.myget.org/F/xunit/" />
-    <add key="api.nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
-    <add key="nuget.org/api/v2" value="https://nuget.org/api/v2/" />
+    <add key="AspNet VNext (CI Builds)" value="https://www.myget.org/F/aspnetvnext/" />
+    <add key="xunit (CI Builds)" value="https://www.myget.org/F/xunit/" />
+    <add key="NuGet.org (v3)" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
+    <add key="NuGet.org (v2)" value="https://www.nuget.org/api/v2/" />
   </packageSources>
 </configuration>
\ No newline at end of file