diff --git a/gtsam/base/std_optional_serialization.h b/gtsam/base/std_optional_serialization.h
index 079cb7745..34556ada4 100644
--- a/gtsam/base/std_optional_serialization.h
+++ b/gtsam/base/std_optional_serialization.h
@@ -56,7 +56,7 @@ namespace std { template<> struct is_trivially_move_constructible<boost::seriali
 #endif
 
 
-#if __cplusplus < 201703L
+#if __cplusplus < 201103L
 // function specializations must be defined in the appropriate
 // namespace - boost::serialization
 namespace boost {