diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0d979f28..2d244540 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -114,7 +114,7 @@ else()
 endif()
 
 if(MSVC)
-  add_definitions(/W4)
+  add_definitions(/W4 /w44640)
   add_definitions(/bigobj)
   # Note on MSVC compiler flags.
   # The code base selective disables warnings as necessary when the compiler is complaining too much
diff --git a/include/chaiscript/dispatchkit/bootstrap_stl.hpp b/include/chaiscript/dispatchkit/bootstrap_stl.hpp
index 13b778a9..35929313 100644
--- a/include/chaiscript/dispatchkit/bootstrap_stl.hpp
+++ b/include/chaiscript/dispatchkit/bootstrap_stl.hpp
@@ -541,7 +541,7 @@ namespace chaiscript
 
           m->add(fun( std::function<const char *(const String *)>( [](const String *s) { return s->c_str(); } ) ), "c_str");
           m->add(fun( std::function<const char *(const String *)>( [](const String *s) { return s->data(); } ) ), "data");
-          m->add(fun( std::function<String (const String *, int, int)>( [](const String *s, int pos, int len) { return s->substr(pos, len); } ) ), "substr");          
+          m->add(fun( std::function<String (const String *, size_t, size_t)>( [](const String *s, size_t pos, size_t len) { return s->substr(pos, len); } ) ), "substr");          
 
           return m;
         }
diff --git a/include/chaiscript/dispatchkit/boxed_number.hpp b/include/chaiscript/dispatchkit/boxed_number.hpp
index 92fda880..adb21c2a 100644
--- a/include/chaiscript/dispatchkit/boxed_number.hpp
+++ b/include/chaiscript/dispatchkit/boxed_number.hpp
@@ -14,10 +14,13 @@
 
 namespace chaiscript 
 {
- 
+
+// Due to the nature of generating every possible arithmetic operation, there
+// are going to be warnings generated on every platform regarding size and sign,
+// this is OK, so we're disabling size/and sign type warnings
 #ifdef CHAISCRIPT_MSVC
 #pragma warning(push)
-#pragma warning(disable : 4244 4018 4389 4146)
+#pragma warning(disable : 4244 4018 4389 4146 4365)
 #endif
 
   /// \brief Represents any numeric type, generically. Used internally for generic operations between POD values
diff --git a/include/chaiscript/language/chaiscript_parser.hpp b/include/chaiscript/language/chaiscript_parser.hpp
index 71334d55..8acd6412 100644
--- a/include/chaiscript/language/chaiscript_parser.hpp
+++ b/include/chaiscript/language/chaiscript_parser.hpp
@@ -194,7 +194,7 @@ namespace chaiscript
       /**
        * test a char in an m_alphabet
        */
-      bool char_in_alphabet(unsigned char c, detail::Alphabet a) { return m_alphabet[a][c]; }
+      bool char_in_alphabet(char c, detail::Alphabet a) { return m_alphabet[a][c]; }
 
       /**
        * Prints the parsed ast_nodes as a tree