diff --git a/interface/pybind11_wrapper.hpp b/interface/pybind11_wrapper.hpp
index 1b0c23d5f18320376c1bcb38e66deb3cbb6a3c49..0ff6ae7e2ff5e7b72cedda82ad18205fb74ed800 100644
--- a/interface/pybind11_wrapper.hpp
+++ b/interface/pybind11_wrapper.hpp
@@ -42,8 +42,8 @@ void add_derivatives(py::module &m, Wrapper &cls) {
     using vd = VirialDerivatives<Model, double, Eigen::Array<double,Eigen::Dynamic,1>>;
     m.def("get_B2vir", &vd::get_B2vir, py::arg("model"), py::arg("T"), py::arg("molefrac").noconvert());
     cls.def("get_B2vir", &vd::get_B2vir, py::arg("T"), py::arg("molefrac").noconvert());
-    cls.def("get_Bnvir", &vd::get_Bnvir_runtime, py::arg("Nderiv"), py::arg("T"), py::arg("molefrac").noconvert());
-    cls.def("get_dmBnvirdTm", &vd::get_dmBnvirdTm_runtime, py::arg("Nderiv"), py::arg("NTderiv"), py::arg("T"), py::arg("molefrac").noconvert());
+    cls.def("get_Bnvir", [](const Model& m, const int Nderiv, const double T, const RAX molefrac) { return vd::get_Bnvir_runtime(Nderiv, m, T, molefrac); }, py::arg("Nderiv"), py::arg("T"), py::arg("molefrac").noconvert());
+    cls.def("get_dmBnvirdTm", [](const Model& m, const int Nderiv, const int NTderiv, const double T, const RAX molefrac) { return vd::get_dmBnvirdTm_runtime(Nderiv, NTderiv, m, T, molefrac); }, py::arg("Nderiv"), py::arg("NTderiv"), py::arg("T"), py::arg("molefrac").noconvert());
     
     m.def("get_B12vir", &vd::get_B12vir, py::arg("model"), py::arg("T"), py::arg("molefrac").noconvert());