diff --git a/test/csharp/ThriftTest/TestClient.cs b/test/csharp/ThriftTest/TestClient.cs
index 60fc995..fe21f41 100644
--- a/test/csharp/ThriftTest/TestClient.cs
+++ b/test/csharp/ThriftTest/TestClient.cs
@@ -163,7 +163,7 @@
 			Console.WriteLine(" = \"" + s + "\"");
 
 			Console.Write("testByte(1)");
-			byte i8 = client.testByte((byte)1);
+			sbyte i8 = client.testByte((sbyte)1);
 			Console.WriteLine(" = " + i8);
 
 			Console.Write("testI32(-1)");
@@ -181,7 +181,7 @@
 			Console.Write("testStruct({\"Zero\", 1, -3, -5})");
 			Xtruct o = new Xtruct();
 			o.String_thing = "Zero";
-			o.Byte_thing = (byte)1;
+			o.Byte_thing = (sbyte)1;
 			o.I32_thing = -3;
 			o.I64_thing = -5;
 			Xtruct i = client.testStruct(o);
@@ -189,7 +189,7 @@
 
 			Console.Write("testNest({1, {\"Zero\", 1, -3, -5}, 5})");
 			Xtruct2 o2 = new Xtruct2();
-			o2.Byte_thing = (byte)1;
+			o2.Byte_thing = (sbyte)1;
 			o2.Struct_thing = o;
 			o2.I32_thing = 5;
 			Xtruct2 i2 = client.testNest(o2);
@@ -359,7 +359,7 @@
 			insane.UserMap[Numberz.FIVE] = 5000L;
 			Xtruct truck = new Xtruct();
 			truck.String_thing = "Truck";
-			truck.Byte_thing = (byte)8;
+			truck.Byte_thing = (sbyte)8;
 			truck.I32_thing = 8;
 			truck.I64_thing = 8;
 			insane.Xtructs = new List<Xtruct>();
@@ -416,7 +416,7 @@
 			Console.WriteLine("}");
 
 
-			byte arg0 = 1;
+			sbyte arg0 = 1;
 			int arg1 = 2;
 			long arg2 = long.MaxValue;
 			Dictionary<short, string> multiDict = new Dictionary<short, string>();
diff --git a/test/csharp/ThriftTest/TestServer.cs b/test/csharp/ThriftTest/TestServer.cs
index 6fb75f4..ceb4368 100644
--- a/test/csharp/ThriftTest/TestServer.cs
+++ b/test/csharp/ThriftTest/TestServer.cs
@@ -50,7 +50,7 @@
 				return thing;
 			}
 
-			public byte testByte(byte thing)
+			public sbyte testByte(sbyte thing)
 			{
 				Console.WriteLine("testByte(" + thing + ")");
 				return thing;
@@ -221,7 +221,7 @@
 
 				Xtruct goodbye = new Xtruct();
 				goodbye.String_thing = "Goodbye4";
-				goodbye.Byte_thing = (byte)4;
+				goodbye.Byte_thing = (sbyte)4;
 				goodbye.I32_thing = 4;
 				goodbye.I64_thing = (long)4;
 
@@ -251,7 +251,7 @@
 				return insane;
 			}
 
-			public Xtruct testMulti(byte arg0, int arg1, long arg2, Dictionary<short, string> arg3, Numberz arg4, long arg5)
+			public Xtruct testMulti(sbyte arg0, int arg1, long arg2, Dictionary<short, string> arg3, Numberz arg4, long arg5)
 			{
 				Console.WriteLine("testMulti()");