diff --git a/include/pybind11/stl_bind.h b/include/pybind11/stl_bind.h
index e581b73eb..49dc9a544 100644
--- a/include/pybind11/stl_bind.h
+++ b/include/pybind11/stl_bind.h
@@ -137,7 +137,6 @@ void vector_modifiers(enable_if_t<std::is_copy_constructible<typename Vector::va
 
     cl.def("extend",
        [](Vector &v, const Vector &src) {
-           v.reserve(v.size() + src.size());
            v.insert(v.end(), src.begin(), src.end());
        },
        arg("L"),