diff --git a/lib/csharp/test/ThriftTest/TestClient.cs b/lib/csharp/test/ThriftTest/TestClient.cs
index cb33473..fc3e418 100644
--- a/lib/csharp/test/ThriftTest/TestClient.cs
+++ b/lib/csharp/test/ThriftTest/TestClient.cs
@@ -167,6 +167,40 @@
             transport.Close();
         }
 
+        public static string BytesToHex(byte[] data) {
+            return BitConverter.ToString(data).Replace("-", string.Empty);
+        }
+
+        public static byte[] PrepareTestData(bool randomDist)
+        {
+            byte[] retval = new byte[0x100];
+            int initLen = Math.Min(0x100,retval.Length);
+
+            // linear distribution, unless random is requested
+            if (!randomDist) {
+                for (var i = 0; i < initLen; ++i) { 
+                    retval[i] = (byte)i;
+                }
+                return retval;
+            }
+
+            // random distribution
+            for (var i = 0; i < initLen; ++i) { 
+                retval[i] = (byte)0;
+            }
+            var rnd = new Random();
+            for (var i = 1; i < initLen; ++i) {
+                while( true) {
+                    int nextPos = rnd.Next() % initLen;
+                    if (retval[nextPos] == 0) {
+                        retval[nextPos] = (byte)i;
+                        break;
+                    }
+                }
+            }
+            return retval;
+        }
+
         public static void ClientTest(TTransport transport)
         {
             TProtocol proto;
@@ -217,6 +251,23 @@
             double dub = client.testDouble(5.325098235);
             Console.WriteLine(" = " + dub);
 
+            byte[] binOut = PrepareTestData(true);
+            Console.Write("testBinary(" + BytesToHex(binOut) + ")");
+            try
+            {
+                byte[] binIn = client.testBinary(binOut);
+                Console.WriteLine(" = " + BytesToHex(binIn));
+                if (binIn.Length != binOut.Length)
+                    throw new Exception("testBinary: length mismatch");
+                for (int ofs = 0; ofs < Math.Min(binIn.Length, binOut.Length); ++ofs)
+                    if (binIn[ofs] != binOut[ofs])
+                        throw new Exception("testBinary: content mismatch at offset " + ofs.ToString());
+            }
+            catch (Thrift.TApplicationException e) 
+            {
+                Console.Write("testBinary(" + BytesToHex(binOut) + "): "+e.Message);
+            }
+
             Console.Write("testStruct({\"Zero\", 1, -3, -5})");
             Xtruct o = new Xtruct();
             o.String_thing = "Zero";
diff --git a/lib/csharp/test/ThriftTest/TestServer.cs b/lib/csharp/test/ThriftTest/TestServer.cs
index d944e72..615ead8 100644
--- a/lib/csharp/test/ThriftTest/TestServer.cs
+++ b/lib/csharp/test/ThriftTest/TestServer.cs
@@ -97,6 +97,13 @@
                 return thing;
             }
 
+            public byte[] testBinary(byte[] thing)
+            {
+                string hex = BitConverter.ToString(thing).Replace("-", string.Empty);
+                Console.WriteLine("testBinary(" + hex + ")");
+                return thing;
+            }
+
             public Xtruct testStruct(Xtruct thing)
             {
                 Console.WriteLine("testStruct({" +