diff --git a/lib/csharp/Makefile.am b/lib/csharp/Makefile.am
index 5ce4276..7cdec05 100644
--- a/lib/csharp/Makefile.am
+++ b/lib/csharp/Makefile.am
@@ -52,6 +52,7 @@
             src/Transport/TBufferedTransport.cs \
             src/Transport/TTransport.cs \
             src/Transport/TSocket.cs \
+            src/Transport/TSocketVersionizer.cs \
             src/Transport/TTransportException.cs \
             src/Transport/TStreamTransport.cs \
             src/Transport/TFramedTransport.cs \
@@ -75,6 +76,10 @@
 MONO_DEFINES=/d:NET_2_0
 endif
 
+if NET_4_5
+MONO_DEFINES=/d:NET_4_5 -sdk:4.5
+endif
+
 all-local: Thrift.dll
 
 Thrift.dll: $(THRIFTCODE)
diff --git a/lib/csharp/ThriftMSBuildTask/ThriftMSBuildTask.csproj b/lib/csharp/ThriftMSBuildTask/ThriftMSBuildTask.csproj
index ae86081..1148eaa 100644
--- a/lib/csharp/ThriftMSBuildTask/ThriftMSBuildTask.csproj
+++ b/lib/csharp/ThriftMSBuildTask/ThriftMSBuildTask.csproj
@@ -28,7 +28,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>ThriftMSBuildTask</RootNamespace>
     <AssemblyName>ThriftMSBuildTask</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <FileUpgradeFlags>
     </FileUpgradeFlags>
diff --git a/lib/csharp/src/Thrift.csproj b/lib/csharp/src/Thrift.csproj
index 195005a..dc0aa6d 100644
--- a/lib/csharp/src/Thrift.csproj
+++ b/lib/csharp/src/Thrift.csproj
@@ -27,7 +27,7 @@
     <OutputType>Library</OutputType>
     <NoStandardLibraries>false</NoStandardLibraries>
     <AssemblyName>Thrift</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <RootNamespace>Thrift</RootNamespace>
     <FileUpgradeFlags>
@@ -109,6 +109,7 @@
     <Compile Include="TException.cs" />
     <Compile Include="TApplicationException.cs" />
     <Compile Include="TProcessor.cs" />
+    <Compile Include="Transport\TSocketVersionizer.cs" />
     <Compile Include="Transport\TBufferedTransport.cs" />
     <Compile Include="Transport\TFramedTransport.cs" />
     <Compile Include="Transport\THttpClient.cs" />
@@ -147,4 +148,4 @@
   <ProjectExtensions>
     <VisualStudio AllowExistingFolder="true" />
   </ProjectExtensions>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/lib/csharp/src/Transport/TServerSocket.cs b/lib/csharp/src/Transport/TServerSocket.cs
index 82a367c..524003e 100644
--- a/lib/csharp/src/Transport/TServerSocket.cs
+++ b/lib/csharp/src/Transport/TServerSocket.cs
@@ -23,6 +23,7 @@
 
 using System;
 using System.Net.Sockets;
+using System.Reflection;
 
 
 namespace Thrift.Transport
@@ -53,7 +54,7 @@
          * Creates a server socket from underlying socket object
          */
         public TServerSocket(TcpListener listener)
-            :this(listener, 0)
+            : this(listener, 0)
         {
         }
 
@@ -78,7 +79,7 @@
          * Creates just a port listening server socket
          */
         public TServerSocket(int port, int clientTimeout)
-            :this(port, clientTimeout, false)
+            : this(port, clientTimeout, false)
         {
         }
 
@@ -90,8 +91,8 @@
             try
             {
                 // Make server socket
-                server = new TcpListener(System.Net.IPAddress.Any, this.port);
-                server.Server.NoDelay = true;
+                this.server = TSocketVersionizer.CreateTcpListener(port);
+                this.server.Server.NoDelay = true;
             }
             catch (Exception)
             {
diff --git a/lib/csharp/src/Transport/TServerTransport.cs b/lib/csharp/src/Transport/TServerTransport.cs
index 05d7d0f..8e84323 100644
--- a/lib/csharp/src/Transport/TServerTransport.cs
+++ b/lib/csharp/src/Transport/TServerTransport.cs
@@ -22,6 +22,8 @@
  */
 
 using System;
+using System.Net.Sockets;
+using System.Reflection;
 
 namespace Thrift.Transport
 {
@@ -34,10 +36,11 @@
         public TTransport Accept()
         {
             TTransport transport = AcceptImpl();
-            if (transport == null) {
-              throw new TTransportException("accept() may not return NULL");
+            if (transport == null)
+            {
+                throw new TTransportException("accept() may not return NULL");
             }
             return transport;
-         }
+        }
     }
 }
diff --git a/lib/csharp/src/Transport/TSocket.cs b/lib/csharp/src/Transport/TSocket.cs
index cf1a440..0b47572 100644
--- a/lib/csharp/src/Transport/TSocket.cs
+++ b/lib/csharp/src/Transport/TSocket.cs
@@ -60,9 +60,9 @@
 
         private void InitSocket()
         {
-            client = new TcpClient();
-            client.ReceiveTimeout = client.SendTimeout = timeout;
-            client.Client.NoDelay = true;
+            this.client = TSocketVersionizer.CreateTcpClient();
+            this.client.ReceiveTimeout = client.SendTimeout = timeout;
+            this.client.Client.NoDelay = true;
         }
 
         public int Timeout
@@ -132,7 +132,7 @@
                 InitSocket();
             }
 
-            if( timeout == 0)            // no timeout -> infinite
+            if (timeout == 0)            // no timeout -> infinite
             {
                 client.Connect(host, port);
             }
@@ -145,7 +145,7 @@
                 {
                     lock (hlp.Mutex)
                     {
-                        if( hlp.CallbackDone)
+                        if (hlp.CallbackDone)
                         {
                             asyncres.AsyncWaitHandle.Close();
                             client.Close();
@@ -174,7 +174,7 @@
 
                 try
                 {
-                    if( hlp.Client.Client != null)
+                    if (hlp.Client.Client != null)
                         hlp.Client.EndConnect(asyncres);
                 }
                 catch (Exception)
@@ -184,14 +184,18 @@
 
                 if (hlp.DoCleanup)
                 {
-                    try {
+                    try
+                    {
                         asyncres.AsyncWaitHandle.Close();
-                    } catch (Exception) {}
+                    }
+                    catch (Exception) { }
 
-                    try {
+                    try
+                    {
                         if (hlp.Client is IDisposable)
                             ((IDisposable)hlp.Client).Dispose();
-                    } catch (Exception) {}
+                    }
+                    catch (Exception) { }
                     hlp.Client = null;
                 }
             }
@@ -219,23 +223,23 @@
             }
         }
 
-    #region " IDisposable Support "
-    private bool _IsDisposed;
+        #region " IDisposable Support "
+        private bool _IsDisposed;
 
-    // IDisposable
-    protected override void Dispose(bool disposing)
-    {
-      if (!_IsDisposed)
-      {
-        if (disposing)
+        // IDisposable
+        protected override void Dispose(bool disposing)
         {
-          if (client != null)
-            ((IDisposable)client).Dispose();
-          base.Dispose(disposing);
+            if (!_IsDisposed)
+            {
+                if (disposing)
+                {
+                    if (client != null)
+                        ((IDisposable)client).Dispose();
+                    base.Dispose(disposing);
+                }
+            }
+            _IsDisposed = true;
         }
-      }
-      _IsDisposed = true;
+        #endregion
     }
-    #endregion
-  }
 }
diff --git a/lib/csharp/src/Transport/TSocketVersionizer.cs b/lib/csharp/src/Transport/TSocketVersionizer.cs
new file mode 100644
index 0000000..1928fac
--- /dev/null
+++ b/lib/csharp/src/Transport/TSocketVersionizer.cs
@@ -0,0 +1,92 @@
+﻿/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Sockets;
+using System.Reflection;
+using System.Text;
+
+namespace Thrift.Transport
+{
+    /**
+    * PropertyInfo for the DualMode property of the System.Net.Sockets.Socket class. Used to determine if the sockets are capable of
+    * automatic IPv4 and IPv6 handling. If DualMode is present the sockets automatically handle IPv4 and IPv6 connections.
+    * If the DualMode is not available the system configuration determines whether IPv4 or IPv6 is used.
+    */
+    internal static class TSocketVersionizer
+    {
+        /*
+        * PropertyInfo for the DualMode property of System.Net.Sockets.Socket.
+        */
+        private static PropertyInfo DualModeProperty = typeof(Socket).GetProperty("DualMode");
+
+        /*
+        * Indicates whether the used framework supports DualMode on sockets or not.
+        */
+        internal static Boolean SupportsDualMode
+        {
+            get
+            {
+                return TSocketVersionizer.DualModeProperty != null;
+            }
+        }
+
+        /*
+        * Creates a TcpClient according to the capabilitites of the used framework
+        */
+        internal static TcpClient CreateTcpClient()
+        {
+            TcpClient client = null;
+
+            if (TSocketVersionizer.SupportsDualMode)
+            {
+                client = new TcpClient(AddressFamily.InterNetworkV6);
+                TSocketVersionizer.DualModeProperty.SetValue(client.Client, true);
+            }
+            else
+            {
+                client = new TcpClient(AddressFamily.InterNetwork);
+            }
+
+            return client;
+        }
+
+        /*
+        * Creates a TcpListener according to the capabilitites of the used framework
+        */
+        internal static TcpListener CreateTcpListener(Int32 port)
+        {
+            TcpListener listener = null;
+
+            if (TSocketVersionizer.SupportsDualMode)
+            {
+                listener = new TcpListener(System.Net.IPAddress.IPv6Any, port);
+                TSocketVersionizer.DualModeProperty.SetValue(listener.Server, true);
+            }
+            else
+            {
+                listener = new TcpListener(System.Net.IPAddress.Any, port);
+            }
+
+            return listener;
+        }
+    }
+}
diff --git a/lib/csharp/src/Transport/TTLSServerSocket.cs b/lib/csharp/src/Transport/TTLSServerSocket.cs
index 631a593..e56c66c 100644
--- a/lib/csharp/src/Transport/TTLSServerSocket.cs
+++ b/lib/csharp/src/Transport/TTLSServerSocket.cs
@@ -115,8 +115,8 @@
             try
             {
                 // Create server socket
-                server = new TcpListener(System.Net.IPAddress.Any, this.port);
-                server.Server.NoDelay = true;
+                this.server = TSocketVersionizer.CreateTcpListener(port);
+                this.server.Server.NoDelay = true;
             }
             catch (Exception)
             {
diff --git a/lib/csharp/src/Transport/TTLSSocket.cs b/lib/csharp/src/Transport/TTLSSocket.cs
index 5652556..d48b7d5 100644
--- a/lib/csharp/src/Transport/TTLSSocket.cs
+++ b/lib/csharp/src/Transport/TTLSSocket.cs
@@ -172,7 +172,7 @@
         /// </summary>
         private void InitSocket()
         {
-            this.client = new TcpClient();
+            this.client = TSocketVersionizer.CreateTcpClient();
             client.ReceiveTimeout = client.SendTimeout = timeout;
             client.Client.NoDelay = true;
         }
@@ -286,7 +286,7 @@
         public void setupTLS()
         {
             RemoteCertificateValidationCallback validator = this.certValidator ?? DefaultCertificateValidator;
-            
+
             if( this.localCertificateSelectionCallback != null)
             {
                 this.secureStream = new SslStream(
@@ -304,7 +304,7 @@
                     validator
                 );
             }
-            
+
             try
             {
                 if (isServer)
diff --git a/lib/csharp/src/Transport/TTransport.cs b/lib/csharp/src/Transport/TTransport.cs
index 2811399..d4977f1 100644
--- a/lib/csharp/src/Transport/TTransport.cs
+++ b/lib/csharp/src/Transport/TTransport.cs
@@ -55,7 +55,7 @@
             }
             catch( IOException)
             {
-                return false;  
+                return false;
             }
 
             _hasPeekByte = true;
diff --git a/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj b/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj
index 6221e14..ff78723 100644
--- a/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj
+++ b/lib/csharp/test/Multiplex/Client/MultiplexClient.csproj
@@ -28,7 +28,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>MultiplexClient</RootNamespace>
     <AssemblyName>MultiplexClient</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <IsWebBootstrapper>false</IsWebBootstrapper>
     <FileUpgradeFlags>
diff --git a/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj b/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj
index dc1d123..6a8177e 100644
--- a/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj
+++ b/lib/csharp/test/Multiplex/Server/MultiplexServer.csproj
@@ -28,7 +28,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>MultiplexServer</RootNamespace>
     <AssemblyName>MultiplexServer</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <IsWebBootstrapper>false</IsWebBootstrapper>
     <FileUpgradeFlags>
diff --git a/lib/csharp/test/ThriftTest/TestClient.cs b/lib/csharp/test/ThriftTest/TestClient.cs
index ec0696a..b54d09d 100644
--- a/lib/csharp/test/ThriftTest/TestClient.cs
+++ b/lib/csharp/test/ThriftTest/TestClient.cs
@@ -185,14 +185,14 @@
 
             // linear distribution, unless random is requested
             if (!randomDist) {
-                for (var i = 0; i < initLen; ++i) { 
+                for (var i = 0; i < initLen; ++i) {
                     retval[i] = (byte)i;
                 }
                 return retval;
             }
 
             // random distribution
-            for (var i = 0; i < initLen; ++i) { 
+            for (var i = 0; i < initLen; ++i) {
                 retval[i] = (byte)0;
             }
             var rnd = new Random();
@@ -270,13 +270,13 @@
                     if (binIn[ofs] != binOut[ofs])
                         throw new Exception("testBinary: content mismatch at offset " + ofs.ToString());
             }
-            catch (Thrift.TApplicationException e) 
+            catch (Thrift.TApplicationException e)
             {
                 Console.Write("testBinary(" + BytesToHex(binOut) + "): "+e.Message);
             }
 
             // binary equals? only with hashcode option enabled ...
-            if( typeof(CrazyNesting).GetMethod("Equals").DeclaringType == typeof(CrazyNesting)) 
+            if( typeof(CrazyNesting).GetMethod("Equals").DeclaringType == typeof(CrazyNesting))
             {
                 CrazyNesting one = new CrazyNesting();
                 CrazyNesting two = new CrazyNesting();
diff --git a/lib/csharp/test/ThriftTest/ThriftTest.csproj b/lib/csharp/test/ThriftTest/ThriftTest.csproj
index d671997..5f9f151 100644
--- a/lib/csharp/test/ThriftTest/ThriftTest.csproj
+++ b/lib/csharp/test/ThriftTest/ThriftTest.csproj
@@ -28,7 +28,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>ThriftTest</RootNamespace>
     <AssemblyName>ThriftTest</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <IsWebBootstrapper>false</IsWebBootstrapper>
     <FileUpgradeFlags>
@@ -136,6 +136,6 @@
 for %25%25I in ("%25OUTPUT_DIR%25") do set SHORT_DIR=%25%25~fsI
 for %25%25I in ("%25THRIFT_FILE%25") do set THRIFT_SHORT=%25%25~fsI
 "$(ProjectDir)\..\..\..\..\compiler\cpp\thrift.exe" --gen csharp -o %25SHORT_DIR%25 %25THRIFT_SHORT%25
-$(MSBuildToolsPath)\Csc.exe /t:library /out:"$(ProjectDir)ThriftImpl.dll" /recurse:"$(ProjectDir)gen-csharp"\* /reference:"$(ProjectDir)..\..\src\bin\Debug\Thrift.dll"</PreBuildEvent>
+"$(MSBuildToolsPath)\Csc.exe" /t:library /out:"$(ProjectDir)ThriftImpl.dll" /recurse:"$(ProjectDir)gen-csharp"\* /reference:"$(ProjectDir)..\..\src\bin\Debug\Thrift.dll"</PreBuildEvent>
   </PropertyGroup>
 </Project>
\ No newline at end of file