diff --git a/src/pugixml.hpp b/src/pugixml.hpp
index 11bf279..1946bfb 100644
--- a/src/pugixml.hpp
+++ b/src/pugixml.hpp
@@ -14,6 +14,10 @@
 #ifndef HEADER_PUGIXML_HPP
 #define HEADER_PUGIXML_HPP
 
+// Define version macro; evaluates to major * 100 + minor so that it's safe to use in less-than comparisons
+#define PUGIXML_VERSION 100
+
+// Include user configuration file (this can define various configuration macros)
 #include "pugiconfig.hpp"
 
 // Include stddef.h for size_t and ptrdiff_t