diff --git a/single/sol/sol.hpp b/single/sol/sol.hpp
index 7f2d6432..ab96a857 100644
--- a/single/sol/sol.hpp
+++ b/single/sol/sol.hpp
@@ -20,8 +20,8 @@
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 // This file was generated with a script.
-// Generated 2017-05-16 10:11:15.504731 UTC
-// This header was generated with sol v2.17.3 (revision 34b81be)
+// Generated 2017-05-17 00:18:39.909842 UTC
+// This header was generated with sol v2.17.3 (revision 51d6f6f)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_HPP
@@ -8396,7 +8396,7 @@ namespace sol {
 			template <typename... Args>
 			static int call_const(std::false_type, lua_State* L, Args&&... args) {
 				typedef typename traits_type::return_type R;
-				return call_assign(std::is_assignable<std::add_lvalue_reference_t<meta::unqualified_t<R>>, R>(), L, std::forward<Args>(args)...);
+				return call_assign(std::is_copy_assignable<meta::unqualified_t<R>>(), L, std::forward<Args>(args)...);
 			}
 
 			template <typename... Args>
diff --git a/sol/call.hpp b/sol/call.hpp
index 2abca3e0..3ba640c2 100644
--- a/sol/call.hpp
+++ b/sol/call.hpp
@@ -335,7 +335,7 @@ namespace sol {
 			template <typename... Args>
 			static int call_const(std::false_type, lua_State* L, Args&&... args) {
 				typedef typename traits_type::return_type R;
-				return call_assign(std::is_assignable<std::add_lvalue_reference_t<meta::unqualified_t<R>>, R>(), L, std::forward<Args>(args)...);
+				return call_assign(std::is_copy_assignable<meta::unqualified_t<R>>(), L, std::forward<Args>(args)...);
 			}
 
 			template <typename... Args>