diff --git a/boxedcpp/bootstrap.hpp b/boxedcpp/bootstrap.hpp
index 2e5b8fb..232304b 100644
--- a/boxedcpp/bootstrap.hpp
+++ b/boxedcpp/bootstrap.hpp
@@ -244,6 +244,12 @@ void add_oper_add(BoxedCPP_System &s)
   register_function(s, &add<T, const T&, const T&>, "+");
 }
 
+template<typename T>
+void add_oper_add_equals(BoxedCPP_System &s)
+{
+  register_function(s, &addsequal<T, T>, "+=");
+}
+
 template<typename T>
 void add_oper_subtract(BoxedCPP_System &s)
 {
@@ -480,6 +486,8 @@ void bootstrap(BoxedCPP_System &s)
   add_opers_arithmetic_pod(s);
 
   add_oper_add<std::string>(s);
+  add_oper_add_equals <std::string>(s);
+
 
   register_function(s, &bool_and<bool, bool>, "&&");
   register_function(s, &bool_or<bool, bool>, "||");
diff --git a/wesley/wesley_engine.hpp b/wesley/wesley_engine.hpp
index 9eddd43..e55b5f0 100644
--- a/wesley/wesley_engine.hpp
+++ b/wesley/wesley_engine.hpp
@@ -286,3 +286,4 @@ public:
 typedef Wesley_System<BoxedCPP_System> Wesley_Engine;
 
 #endif /* WESLEY_ENGINE_HPP_ */
+