diff --git a/include/pybind11/cast.h b/include/pybind11/cast.h
index a0e32281bc..b89e4946ad 100644
--- a/include/pybind11/cast.h
+++ b/include/pybind11/cast.h
@@ -1545,7 +1545,7 @@ class unpacking_collector {
             throw cast_error_unable_to_convert_call_arg(a.name, a.type);
 #endif
         }
-        m_kwargs[a.name] = a.value;
+        m_kwargs[a.name] = std::move(a.value);
     }
 
     void process(list & /*args_list*/, detail::kwargs_proxy kp) {