diff --git a/Library/Measure.cpp b/Library/Measure.cpp
index 9ae049bb..e2cc1d38 100644
--- a/Library/Measure.cpp
+++ b/Library/Measure.cpp
@@ -830,7 +830,7 @@ CMeasure* CMeasure::Create(const WCHAR* measure, CMeterWindow* meterWindow, cons
 	{
 		return new CMeasureCalc(meterWindow, name);
 	}
-	else if (_wcsicmp(L"script", measure) == 0)
+	else if (_wcsicmp(L"Script", measure) == 0)
 	{
 		return new CMeasureScript(meterWindow, name);
 	}
diff --git a/Library/MeasureScript.cpp b/Library/MeasureScript.cpp
index 842aa74f..b2add2b7 100644
--- a/Library/MeasureScript.cpp
+++ b/Library/MeasureScript.cpp
@@ -34,7 +34,8 @@ CMeasureScript::CMeasureScript(CMeterWindow* meterWindow, const WCHAR* name) : C
 	m_LuaScript(),
 	m_HasInitializeFunction(false),
 	m_HasUpdateFunction(false),
-	m_HasGetStringFunction(false)
+	m_HasGetStringFunction(false),
+	m_ValueType(LUA_TNIL)
 {
 	LuaManager::Init();
 }
@@ -95,11 +96,19 @@ bool CMeasureScript::Update()
 		return false;
 	}
 
-	if (!(m_HasUpdateFunction && m_LuaScript->RunFunctionWithReturn(g_UpdateFunctionName, m_Value, m_StringValue)) &&
-		!(m_HasGetStringFunction && m_LuaScript->RunFunctionWithReturn(g_GetStringFunctionName, m_Value, m_StringValue)))
+	if (m_HasUpdateFunction)
 	{
-		m_Value = 0;
-		m_StringValue.clear();
+		m_ValueType = m_LuaScript->RunFunctionWithReturn(g_UpdateFunctionName, m_Value, m_StringValue);
+
+		if (m_ValueType == LUA_TSTRING)
+		{
+			m_Value = 0;
+		}
+		else if (m_ValueType == LUA_TNIL && m_HasGetStringFunction)
+		{
+			// For backwards compatbility
+			m_ValueType = m_LuaScript->RunFunctionWithReturn(g_GetStringFunctionName, m_Value, m_StringValue);
+		}
 	}
 
 	return PostUpdate();
@@ -113,7 +122,7 @@ bool CMeasureScript::Update()
 */
 const WCHAR* CMeasureScript::GetStringValue(AUTOSCALE autoScale, double scale, int decimals, bool percentual)
 {
-	if (!m_StringValue.empty())
+	if (m_ValueType == LUA_TSTRING)
 	{
 		return CheckSubstitute(m_StringValue.c_str());
 	}
diff --git a/Library/MeasureScript.h b/Library/MeasureScript.h
index 0c0792c8..8c18d805 100644
--- a/Library/MeasureScript.h
+++ b/Library/MeasureScript.h
@@ -37,11 +37,13 @@ public:
 
 protected:
 	LuaScript* m_LuaScript;
-	
+
 	bool m_HasInitializeFunction;
 	bool m_HasUpdateFunction;
 	bool m_HasGetStringFunction;
 
+	int m_ValueType;
+
 	std::wstring m_StringValue;
 
 	std::string m_ScriptFile;
diff --git a/Library/lua/LuaScript.cpp b/Library/lua/LuaScript.cpp
index 03334b89..b141ae92 100644
--- a/Library/lua/LuaScript.cpp
+++ b/Library/lua/LuaScript.cpp
@@ -147,12 +147,12 @@ void LuaScript::RunFunction(const char* funcName)
 ** RunFunctionWithReturn
 **
 ** Runs given function in script file and stores the retruned number or string.
-** Returns true if the executed function returns a valid value.
+** Returns LUA_TNIL when no return.
 **
 */
-bool LuaScript::RunFunctionWithReturn(const char* funcName, double& numValue, std::wstring& strValue)
+int LuaScript::RunFunctionWithReturn(const char* funcName, double& numValue, std::wstring& strValue)
 {
-	bool ret = false;
+	int ret = LUA_TNIL;
 
 	if (m_Initialized)
 	{
@@ -172,17 +172,13 @@ bool LuaScript::RunFunctionWithReturn(const char* funcName, double& numValue, st
 			if (lua_isnumber(m_State, -1))
 			{
 				numValue = lua_tonumber(m_State, -1);
-
-				strValue.clear();
-				ret = true;
+				ret = LUA_TNUMBER;
 			}
 			else if (lua_isstring(m_State, -1))
 			{
 				const char* str = lua_tostring(m_State, -1);
 				strValue = ConvertToWide(str);
-
-				numValue = 0;
-				ret = true;
+				ret = LUA_TSTRING;
 			}
 
 			lua_pop(m_State, 2);
diff --git a/Library/lua/LuaScript.h b/Library/lua/LuaScript.h
index 25c0ab53..9102a80f 100644
--- a/Library/lua/LuaScript.h
+++ b/Library/lua/LuaScript.h
@@ -32,7 +32,7 @@ public:
 
 	bool IsFunction(const char* funcName);
 	void RunFunction(const char* funcName);
-	bool RunFunctionWithReturn(const char* funcName, double& numValue, std::wstring& strValue);
+	int RunFunctionWithReturn(const char* funcName, double& numValue, std::wstring& strValue);
 	void RunString(const char* str);
 
 protected: