diff --git a/include/chaiscript/dispatchkit/boxed_number.hpp b/include/chaiscript/dispatchkit/boxed_number.hpp
index 87d0cb3..69cfefa 100644
--- a/include/chaiscript/dispatchkit/boxed_number.hpp
+++ b/include/chaiscript/dispatchkit/boxed_number.hpp
@@ -49,7 +49,7 @@ namespace chaiscript
   class Boxed_Number
   {
     private:
-#ifdef CHAISCRIPT_PROTECT_DIVIDEBYZERO
+#ifndef CHAISCRIPT_NO_PROTECT_DIVIDEBYZERO
       template<typename T>
       static void check_divide_by_zero(T t)
       {