diff --git a/include/chaiscript/dispatchkit/bootstrap_stl.hpp b/include/chaiscript/dispatchkit/bootstrap_stl.hpp
index b86b1e44..b9e0a9f5 100644
--- a/include/chaiscript/dispatchkit/bootstrap_stl.hpp
+++ b/include/chaiscript/dispatchkit/bootstrap_stl.hpp
@@ -315,6 +315,7 @@ namespace chaiscript
         void reservable_type(const std::string &/*type*/, Module& m)
         {
           m.add(fun([](ContainerType *a, typename ContainerType::size_type n) { return a->reserve(n); } ), "reserve");
+          m.add(fun([](const ContainerType *a) { return a->capacity(); } ), "capacity");
         }
       template<typename ContainerType>
         ModulePtr reservable_type(const std::string &type)
diff --git a/unittests/vector_reserve.chai b/unittests/vector_reserve.chai
index 764002af..68c8dbdb 100644
--- a/unittests/vector_reserve.chai
+++ b/unittests/vector_reserve.chai
@@ -3,5 +3,5 @@ load_module("stl_extra");
 auto uint16v = u16vector();
 
 uint16v.reserve(5);
-assert_true(uint16v.size() >= 5);
+assert_true(uint16v.capacity() >= 5);