diff --git a/src/mscorlib/model.xml b/src/mscorlib/model.xml
index 4b363a229d7c..b951881869ad 100644
--- a/src/mscorlib/model.xml
+++ b/src/mscorlib/model.xml
@@ -1847,6 +1847,22 @@
       <Member Name="FailFast(System.String,System.Exception)"  />
       <Member Name="Exit(System.Int32)" />
     </Type>
+    <Type Name="Internal.Runtime.Augments.EnvironmentAugments">
+      <Member MemberType="Property" Name="CurrentManagedThreadId"  />
+      <Member MemberType="Property" Name="ExitCode" />
+      <Member MemberType="Property" Name="HasShutdownStarted" />
+      <Member MemberType="Property" Name="StackTrace" />
+      <Member MemberType="Property" Name="TickCount" />
+      <Member Name="get_CurrentManagedThreadId"  />
+      <Member Name="get_ExitCode" />
+      <Member Name="set_ExitCode(System.Int32)" />
+      <Member Name="get_HasShutdownStarted"  />
+      <Member Name="get_StackTrace" />
+      <Member Name="get_TickCount" />
+      <Member Name="Exit(System.Int32)" />
+      <Member Name="FailFast(System.String,System.Exception)"  />
+      <Member Name="GetCommandLineArgs" />
+    </Type>
     <Type Name="System.EventArgs">
       <Member MemberType="Field" Name="Empty" />
       <Member Name="#ctor" />
diff --git a/src/mscorlib/mscorlib.shared.sources.props b/src/mscorlib/mscorlib.shared.sources.props
index 78983c0639c8..eed8917cd154 100644
--- a/src/mscorlib/mscorlib.shared.sources.props
+++ b/src/mscorlib/mscorlib.shared.sources.props
@@ -450,6 +450,9 @@
     <SystemSources Condition="'$(FeatureCominterop)' == 'true'" Include="$(BclSourcesRoot)\System\Variant.cs" />
     <SystemSources Condition="'$(FeatureClassicCominterop)' == 'true'" Include="$(BclSourcesRoot)\System\OleAutBinder.cs" />
   </ItemGroup>
+  <ItemGroup>
+    <SystemSources Condition="'$(FeatureCoreclr)' == 'true'" Include="$(BclSourcesRoot)\Internal\Runtime\Augments\EnvironmentAugments.cs" />
+  </ItemGroup>
   <ItemGroup>
     <ReflectionSources Include="$(BclSourcesRoot)\System\Reflection\__Filters.cs" />
     <ReflectionSources Include="$(BclSourcesRoot)\System\Reflection\AmbiguousMatchException.cs" />
diff --git a/src/mscorlib/src/Internal/Runtime/Augments/EnvironmentAugments.cs b/src/mscorlib/src/Internal/Runtime/Augments/EnvironmentAugments.cs
new file mode 100644
index 000000000000..28104683c7c5
--- /dev/null
+++ b/src/mscorlib/src/Internal/Runtime/Augments/EnvironmentAugments.cs
@@ -0,0 +1,21 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+
+namespace Internal.Runtime.Augments
+{
+    /// <summary>For internal use only.  Exposes runtime functionality to the Environments implementation in corefx.</summary>
+    public static class EnvironmentAugments
+    {
+        public static int CurrentManagedThreadId => Environment.CurrentManagedThreadId;
+        public static void Exit(int exitCode) => Environment.Exit(exitCode);
+        public static int ExitCode { get { return Environment.ExitCode; } set { Environment.ExitCode = value; } }
+        public static void FailFast(string message, Exception error) => Environment.FailFast(message, error);
+        public static string[] GetCommandLineArgs() => Environment.GetCommandLineArgs();
+        public static bool HasShutdownStarted => Environment.HasShutdownStarted;
+        public static string StackTrace => Environment.StackTrace;
+        public static int TickCount => Environment.TickCount;
+    }
+}