diff --git a/.vscode/settings.json b/.vscode/settings.json
index 5369ad3..c8d57a1 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,6 +1,7 @@
 {
     "files.associations": {
         "*.rmd": "markdown",
-        "stdexcept": "cpp"
+        "stdexcept": "cpp",
+        "sstream": "cpp"
     }
 }
\ No newline at end of file
diff --git a/include/muParserDef.h b/include/muParserDef.h
index d36dbe3..599f04b 100644
--- a/include/muParserDef.h
+++ b/include/muParserDef.h
@@ -509,7 +509,7 @@ namespace mu
 	static const int MaxLenExpression = 20000;
 	static const int MaxLenIdentifier = 100;
 	static const string_type ParserVersion = string_type(_T("2.3.4 (Develop)"));
-	static const string_type ParserVersionDate = string_type(_T("20231013"));
+	static const string_type ParserVersionDate = string_type(_T("20231224"));
 } // end of namespace
 
 #if defined(_MSC_VER)
diff --git a/src/muParser.cpp b/src/muParser.cpp
index aead7d5..1f6400b 100644
--- a/src/muParser.cpp
+++ b/src/muParser.cpp
@@ -33,6 +33,8 @@
 #include <cmath>
 #include <algorithm>
 #include <numeric>
+#include <cstdlib>
+
 
 using namespace std;
 
@@ -54,8 +56,9 @@ namespace mu
 	*/
 	int Parser::IsVal(const char_type* a_szExpr, int* a_iPos, value_type* a_fVal)
 	{
-/*      // 2023-12-23 Issue #136:  This code breaks localization!
+        // 2023-12-23 Issue #136:  This code breaks localization!
 
+/*
 		// fix for #123; std::Stringstream is broken on Mac; use std::stod instead
 		try
 		{
@@ -76,8 +79,7 @@ namespace mu
 
 		value_type fVal(0);
 
-//		stringstream_type stream(a_szExpr);
-		std::istringstream stream(a_szExpr);
+		stringstream_type stream(a_szExpr);
 		stream.imbue(Parser::s_locale);
 		stream >> fVal;
 		stringstream_type::pos_type iEnd = stream.tellg(); // Position after reading