diff --git a/include/boost/utility/result_of.hpp b/include/boost/utility/result_of.hpp
index 8571a56..fc64bb3 100644
--- a/include/boost/utility/result_of.hpp
+++ b/include/boost/utility/result_of.hpp
@@ -119,7 +119,7 @@ template<typename F> struct cpp0x_result_of;
 
 // There doesn't seem to be any other way to turn this off such that the presence of
 // the user-defined operator,() below doesn't cause spurious warning all over the place,
-// so unconditionally turn it off.
+// so unconditionally turn it off. (https://svn.boost.org/trac10/ticket/7663)
 #ifdef BOOST_MSVC
 #  pragma warning(disable: 4913) // user defined binary operator ',' exists but no overload could convert all operands, default built-in binary operator ',' used
 #endif