--- boost/thread/win32/shared_mutex.hpp	2013-03-23 02:48:21.000000000 +0100
+++ boost/thread/win32/shared_mutex.hpp	2016-07-28 13:51:35.433426400 +0200
@@ -733,6 +733,7 @@
                 new_state.upgrade=false;
                 bool const last_reader=!--new_state.shared_count;
 
+                new_state.shared_waiting=0;
                 if(last_reader)
                 {
                     if(new_state.exclusive_waiting)
@@ -740,7 +741,6 @@
                         --new_state.exclusive_waiting;
                         new_state.exclusive_waiting_blocked=false;
                     }
-                    new_state.shared_waiting=0;
                 }
 
                 state_data const current_state=interlocked_compare_exchange(&state,new_state,old_state);