diff --git a/Core/NLua/CheckType.cs b/Core/NLua/CheckType.cs
index 8b1e7b6e..89136468 100755
--- a/Core/NLua/CheckType.cs
+++ b/Core/NLua/CheckType.cs
@@ -102,11 +102,34 @@ internal ExtractValue CheckLuaType (LuaState luaState, int stackPos, Type paramT
 				paramType = paramType.GetElementType ();
 
 			var underlyingType = Nullable.GetUnderlyingType (paramType);
-
-			if (underlyingType != null)
+			
+			if (underlyingType != null) {
 				paramType = underlyingType;	 // Silently convert nullable types to their non null requics
+			}
 
 			var extractKey = GetExtractDictionaryKey (paramType);
+			
+			bool netParamIsNumeric = paramType == typeof (int) ||
+									 paramType == typeof (uint) ||
+									 paramType == typeof (long) ||
+									 paramType == typeof (ulong) ||
+									 paramType == typeof (short) ||
+									 paramType == typeof (ushort) ||
+									 paramType == typeof (float) ||
+									 paramType == typeof (double) ||
+									 paramType == typeof (decimal) ||
+									 paramType == typeof (byte);
+
+			// If it is a nullable
+			if (underlyingType != null) {
+				// null can always be assigned to nullable
+				if (luatype == LuaTypes.Nil) {
+					// Return the correct extractor anyways
+					if (netParamIsNumeric || paramType == typeof (bool))
+						return extractValues [extractKey];
+					return extractNetObject;
+				}
+			}
 
 			if (paramType.Equals (typeof(object)))
 				return extractValues [extractKey];
@@ -127,15 +150,6 @@ internal ExtractValue CheckLuaType (LuaState luaState, int stackPos, Type paramT
 					return extractValues [GetExtractDictionaryKey (typeof(double))];
 			}
 			bool netParamIsString = paramType == typeof (string) || paramType == typeof (char []);
-			bool netParamIsNumeric = paramType == typeof (int) ||
-									 paramType == typeof (uint) ||
-									 paramType == typeof (long) ||
-									 paramType == typeof (ulong) ||
-									 paramType == typeof (short) ||
-									 paramType == typeof (float) ||
-									 paramType == typeof (double) ||
-									 paramType == typeof (decimal) ||
-									 paramType == typeof (byte);
 
 			if (netParamIsNumeric) {
 				if (LuaLib.LuaIsNumber (luaState, stackPos) && !netParamIsString)
@@ -149,13 +163,13 @@ internal ExtractValue CheckLuaType (LuaState luaState, int stackPos, Type paramT
 				else if (luatype == LuaTypes.Nil)
 					return extractNetObject; // kevinh - silently convert nil to a null string pointer
 			} else if (paramType == typeof(LuaTable)) {
-				if (luatype == LuaTypes.Table)
+				if (luatype == LuaTypes.Table || luatype == LuaTypes.Nil)
 					return extractValues [extractKey];
 			} else if (paramType == typeof(LuaUserData)) {
-				if (luatype == LuaTypes.UserData)
+				if (luatype == LuaTypes.UserData || luatype == LuaTypes.Nil)
 					return extractValues [extractKey];
 			} else if (paramType == typeof(LuaFunction)) {
-				if (luatype == LuaTypes.Function)
+				if (luatype == LuaTypes.Function || luatype == LuaTypes.Nil)
 					return extractValues [extractKey];
 			} else if (typeof(Delegate).IsAssignableFrom (paramType) && luatype == LuaTypes.Function)
 				return new ExtractValue (new DelegateGenerator (translator, paramType).ExtractGenerated);
diff --git a/Core/NLua/ObjectTranslator.cs b/Core/NLua/ObjectTranslator.cs
index c3c2123c..25dae263 100755
--- a/Core/NLua/ObjectTranslator.cs
+++ b/Core/NLua/ObjectTranslator.cs
@@ -829,8 +829,11 @@ internal object GetObject (LuaState luaState, int index)
 		 */
 		internal LuaTable GetTable (LuaState luaState, int index)
 		{
-			LuaLib.LuaPushValue (luaState, index);
-			return new LuaTable (LuaLib.LuaRef (luaState, 1), interpreter);
+			LuaLib.LuaPushValue (luaState, index);
+			int reference = LuaLib.LuaRef (luaState, 1);
+			if (reference == -1)
+				return null;
+			return new LuaTable (reference, interpreter);
 		}
 
 		/*
@@ -838,8 +841,11 @@ internal LuaTable GetTable (LuaState luaState, int index)
 		 */
 		internal LuaUserData GetUserData (LuaState luaState, int index)
 		{
-			LuaLib.LuaPushValue (luaState, index);
-			return new LuaUserData (LuaLib.LuaRef (luaState, 1), interpreter);
+			LuaLib.LuaPushValue (luaState, index);
+			int reference = LuaLib.LuaRef (luaState, 1);
+			if (reference == -1)
+				return null;
+			return new LuaUserData(reference, interpreter);
 		}
 
 		/*
@@ -847,8 +853,11 @@ internal LuaUserData GetUserData (LuaState luaState, int index)
 		 */
 		internal LuaFunction GetFunction (LuaState luaState, int index)
 		{
-			LuaLib.LuaPushValue (luaState, index);
-			return new LuaFunction (LuaLib.LuaRef (luaState, 1), interpreter);
+			LuaLib.LuaPushValue (luaState, index);
+			int reference = LuaLib.LuaRef (luaState, 1);
+			if (reference == -1)
+				return null;
+			return new LuaFunction (reference, interpreter);
 		}
 
 		/*
diff --git a/tests/LuaTests.cs b/tests/LuaTests.cs
index 549cc6e7..58a7ce84 100755
--- a/tests/LuaTests.cs
+++ b/tests/LuaTests.cs
@@ -153,6 +153,26 @@ public void ThrowException ()
 			}
 		}
 
+		/*
+		* Tests passing a LuaFunction
+		*/
+		[Test]
+		public void CallLuaFunction()
+		{
+			using (Lua lua = new Lua ()) {
+				lua.DoString ("function someFunc(v1,v2) return v1 + v2 end");
+				lua ["funcObject"] = lua.GetFunction ("someFunc");
+
+				lua.DoString ("luanet.load_assembly('mscorlib')");
+				lua.DoString ("luanet.load_assembly('NLuaTest')");
+				lua.DoString ("TestClass=luanet.import_type('NLuaTest.Mock.TestClass')");
+				lua.DoString ("b = TestClass():TestLuaFunction(funcObject)[0]");
+				Assert.AreEqual (3, lua ["b"]);
+				lua.DoString ("a = TestClass():TestLuaFunction(nil)");
+				Assert.AreEqual (null, lua ["a"]);
+			}
+		}
+
 		/*
         * Tests capturing an exception
         */
@@ -620,6 +640,29 @@ public void TestRegisterFunction ()
 				Assert.AreEqual (5.0f, Convert.ToSingle (vals1 [0]));
 			}
 		}
+	
+		/*
+		 * Tests passing a null object as a parameter to a
+		 * method that accepts a nullable.
+		 */
+		[Test]
+		public void TestNullableParameter ()
+		{
+			using (Lua lua = new Lua ()) {
+				lua.DoString ("luanet.load_assembly('NLuaTest')");
+				lua.DoString ("TestClass=luanet.import_type('NLuaTest.Mock.TestClass')");
+				lua.DoString ("test=TestClass()");
+				lua.DoString ("a = test:NullableMethod(nil)");
+				Assert.AreEqual (null, lua ["a"]);
+				lua ["timeVal"] = TimeSpan.FromSeconds (5);
+				lua.DoString ("b = test:NullableMethod(timeVal)");
+				Assert.AreEqual (TimeSpan.FromSeconds (5), lua ["b"]);
+				lua.DoString ("d = test:NullableMethod2(2)");
+				Assert.AreEqual (2, lua ["d"]);
+				lua.DoString ("c = test:NullableMethod2(nil)");
+				Assert.AreEqual (null, lua ["c"]);
+			}
+		}
 
 		/*
         * Tests if DoString is correctly returning values
diff --git a/tests/TestLua.cs b/tests/TestLua.cs
index 2629ded8..13fe4b20 100755
--- a/tests/TestLua.cs
+++ b/tests/TestLua.cs
@@ -374,6 +374,24 @@ public static TestClass makeFromString (String str)
 			set { }
 		}
 
+		public TimeSpan? NullableMethod (TimeSpan? input)
+		{
+			return input;
+		}
+
+		public int? NullableMethod2 (int? input)
+		{
+			return input;
+		}
+
+		public object[] TestLuaFunction (LuaFunction func)
+		{
+			if (func != null) {
+				return func.Call (1, 2);
+			}
+			return null;
+		}
+
 		public int sum (int x, int y)
 		{
  return x + y;