From https://github.com/boostorg/thread/commit/49ccf9c30a0ca556873dbf64b12b0d741d1b3e66
index bbf0ffc..989baba 100644
--- a/src/third_party/boost/boost/thread/future.hpp
+++ b/src/third_party/boost/boost/thread/future.hpp
@@ -4669,7 +4669,7 @@ namespace detail
       }
       run_it& operator=(BOOST_THREAD_RV_REF(run_it) x) BOOST_NOEXCEPT {
         if (this != &x) {
-          that_=x.that;
+          that_=x.that_;
           x.that_.reset();
         }
         return *this;