diff --git a/bindings/python/src/expose-qpobject.hpp b/bindings/python/src/expose-qpobject.hpp
index 3f37d3b72..84237b640 100644
--- a/bindings/python/src/expose-qpobject.hpp
+++ b/bindings/python/src/expose-qpobject.hpp
@@ -102,18 +102,18 @@ exposeQpObjectDense(nanobind::module_ m)
                                             optional<T>,
                                             optional<T>)>(&dense::QP<T>::init),
          "function for initialize the QP model.",
-         nanobind::arg("H") = nullopt,
-         nanobind::arg("g") = nullopt,
-         nanobind::arg("A") = nullopt,
-         nanobind::arg("b") = nullopt,
-         nanobind::arg("C") = nullopt,
-         nanobind::arg("l") = nullopt,
-         nanobind::arg("u") = nullopt,
+         nanobind::arg("H"),
+         nanobind::arg("g"),
+         nanobind::arg("A") = nanobind::none(),
+         nanobind::arg("b") = nanobind::none(),
+         nanobind::arg("C") = nanobind::none(),
+         nanobind::arg("l") = nanobind::none(),
+         nanobind::arg("u") = nanobind::none(),
          nanobind::arg("compute_preconditioner") = true,
-         nanobind::arg("rho") = nullopt,
-         nanobind::arg("mu_eq") = nullopt,
-         nanobind::arg("mu_in") = nullopt,
-         nanobind::arg("manual_minimal_H_eigenvalue") = nullopt)
+         nanobind::arg("rho") = nanobind::none(),
+         nanobind::arg("mu_eq") = nanobind::none(),
+         nanobind::arg("mu_in") = nanobind::none(),
+         nanobind::arg("manual_minimal_H_eigenvalue") = nanobind::none())
     .def("init",
          static_cast<void (dense::QP<T>::*)(optional<dense::MatRef<T>>,
                                             optional<dense::VecRef<T>>,
@@ -130,20 +130,20 @@ exposeQpObjectDense(nanobind::module_ m)
                                             optional<T>,
                                             optional<T>)>(&dense::QP<T>::init),
          "function for initialize the QP model.",
-         nanobind::arg("H") = nullopt,
-         nanobind::arg("g") = nullopt,
-         nanobind::arg("A") = nullopt,
-         nanobind::arg("b") = nullopt,
-         nanobind::arg("C") = nullopt,
-         nanobind::arg("l") = nullopt,
-         nanobind::arg("u") = nullopt,
-         nanobind::arg("l_box") = nullopt,
-         nanobind::arg("u_box") = nullopt,
+         nanobind::arg("H") = nanobind::none(),
+         nanobind::arg("g") = nanobind::none(),
+         nanobind::arg("A") = nanobind::none(),
+         nanobind::arg("b") = nanobind::none(),
+         nanobind::arg("C") = nanobind::none(),
+         nanobind::arg("l") = nanobind::none(),
+         nanobind::arg("u") = nanobind::none(),
+         nanobind::arg("l_box") = nanobind::none(),
+         nanobind::arg("u_box") = nanobind::none(),
          nanobind::arg("compute_preconditioner") = true,
-         nanobind::arg("rho") = nullopt,
-         nanobind::arg("mu_eq") = nullopt,
-         nanobind::arg("mu_in") = nullopt,
-         nanobind::arg("manual_minimal_H_eigenvalue") = nullopt)
+         nanobind::arg("rho") = nanobind::none(),
+         nanobind::arg("mu_eq") = nanobind::none(),
+         nanobind::arg("mu_in") = nanobind::none(),
+         nanobind::arg("manual_minimal_H_eigenvalue") = nanobind::none())
     .def("solve",
          static_cast<void (dense::QP<T>::*)()>(&dense::QP<T>::solve),
          "function used for solving the QP problem, using default parameters.")
@@ -170,18 +170,18 @@ exposeQpObjectDense(nanobind::module_ m)
                                          optional<T>)>(&dense::QP<T>::update),
       "function used for updating matrix or vector entry of the model using "
       "dense matrix entries.",
-      nanobind::arg("H") = nullopt,
-      nanobind::arg("g") = nullopt,
-      nanobind::arg("A") = nullopt,
-      nanobind::arg("b") = nullopt,
-      nanobind::arg("C") = nullopt,
-      nanobind::arg("l") = nullopt,
-      nanobind::arg("u") = nullopt,
+      nanobind::arg("H") = nanobind::none(),
+      nanobind::arg("g") = nanobind::none(),
+      nanobind::arg("A") = nanobind::none(),
+      nanobind::arg("b") = nanobind::none(),
+      nanobind::arg("C") = nanobind::none(),
+      nanobind::arg("l") = nanobind::none(),
+      nanobind::arg("u") = nanobind::none(),
       nanobind::arg("update_preconditioner") = false,
-      nanobind::arg("rho") = nullopt,
-      nanobind::arg("mu_eq") = nullopt,
-      nanobind::arg("mu_in") = nullopt,
-      nanobind::arg("manual_minimal_H_eigenvalue") = nullopt)
+      nanobind::arg("rho") = nanobind::none(),
+      nanobind::arg("mu_eq") = nanobind::none(),
+      nanobind::arg("mu_in") = nanobind::none(),
+      nanobind::arg("manual_minimal_H_eigenvalue") = nanobind::none())
     .def(
       "update",
       static_cast<void (dense::QP<T>::*)(optional<dense::MatRef<T>>,
@@ -200,20 +200,20 @@ exposeQpObjectDense(nanobind::module_ m)
                                          optional<T>)>(&dense::QP<T>::update),
       "function used for updating matrix or vector entry of the model using "
       "dense matrix entries.",
-      nanobind::arg("H") = nullopt,
-      nanobind::arg("g") = nullopt,
-      nanobind::arg("A") = nullopt,
-      nanobind::arg("b") = nullopt,
-      nanobind::arg("C") = nullopt,
-      nanobind::arg("l") = nullopt,
-      nanobind::arg("u") = nullopt,
-      nanobind::arg("l_box") = nullopt,
-      nanobind::arg("u_box") = nullopt,
+      nanobind::arg("H") = nanobind::none(),
+      nanobind::arg("g") = nanobind::none(),
+      nanobind::arg("A") = nanobind::none(),
+      nanobind::arg("b") = nanobind::none(),
+      nanobind::arg("C") = nanobind::none(),
+      nanobind::arg("l") = nanobind::none(),
+      nanobind::arg("u") = nanobind::none(),
+      nanobind::arg("l_box") = nanobind::none(),
+      nanobind::arg("u_box") = nanobind::none(),
       nanobind::arg("update_preconditioner") = false,
-      nanobind::arg("rho") = nullopt,
-      nanobind::arg("mu_eq") = nullopt,
-      nanobind::arg("mu_in") = nullopt,
-      nanobind::arg("manual_minimal_H_eigenvalue") = nullopt)
+      nanobind::arg("rho") = nanobind::none(),
+      nanobind::arg("mu_eq") = nanobind::none(),
+      nanobind::arg("mu_in") = nanobind::none(),
+      nanobind::arg("manual_minimal_H_eigenvalue") = nanobind::none())
     .def("cleanup",
          &dense::QP<T>::cleanup,
          "function used for cleaning the workspace and result "
@@ -251,8 +251,8 @@ exposeQpObjectSparse(nanobind::module_ m)
     .def(::nanobind::init<const sparse::SparseMat<bool, I>&,
                           const sparse::SparseMat<bool, I>&,
                           const sparse::SparseMat<bool, I>&>(),
-         nanobind::arg("H_mask") = nullopt,
-         nanobind::arg("A_mask") = nullopt,
+         nanobind::arg("H_mask") = nanobind::none(),
+         nanobind::arg("A_mask") = nanobind::none(),
          nanobind::arg("C_mask") = 0,
          "Constructor using QP model sparsity structure.") // constructor
     .def_ro("model", &sparse::QP<T, I>::model, "class containing the QP model")
@@ -266,35 +266,35 @@ exposeQpObjectSparse(nanobind::module_ m)
          &sparse::QP<T, I>::init,
          "function for initializing the model when passing sparse matrices in "
          "entry.",
-         nanobind::arg("H") = nullopt,
-         nanobind::arg("g") = nullopt,
-         nanobind::arg("A") = nullopt,
-         nanobind::arg("b") = nullopt,
-         nanobind::arg("C") = nullopt,
-         nanobind::arg("l") = nullopt,
-         nanobind::arg("u") = nullopt,
+         nanobind::arg("H") = nanobind::none(),
+         nanobind::arg("g") = nanobind::none(),
+         nanobind::arg("A") = nanobind::none(),
+         nanobind::arg("b") = nanobind::none(),
+         nanobind::arg("C") = nanobind::none(),
+         nanobind::arg("l") = nanobind::none(),
+         nanobind::arg("u") = nanobind::none(),
          nanobind::arg("compute_preconditioner") = true,
-         nanobind::arg("rho") = nullopt,
-         nanobind::arg("mu_eq") = nullopt,
-         nanobind::arg("mu_in") = nullopt,
-         nanobind::arg("manual_minimal_H_eigenvalue") = nullopt)
+         nanobind::arg("rho") = nanobind::none(),
+         nanobind::arg("mu_eq") = nanobind::none(),
+         nanobind::arg("mu_in") = nanobind::none(),
+         nanobind::arg("manual_minimal_H_eigenvalue") = nanobind::none())
 
     .def("update",
          &sparse::QP<T, I>::update,
          "function for updating the model when passing sparse matrices in "
          "entry.",
-         nanobind::arg("H") = nullopt,
-         nanobind::arg("g") = nullopt,
-         nanobind::arg("A") = nullopt,
-         nanobind::arg("b") = nullopt,
-         nanobind::arg("C") = nullopt,
-         nanobind::arg("l") = nullopt,
-         nanobind::arg("u") = nullopt,
+         nanobind::arg("H") = nanobind::none(),
+         nanobind::arg("g") = nanobind::none(),
+         nanobind::arg("A") = nanobind::none(),
+         nanobind::arg("b") = nanobind::none(),
+         nanobind::arg("C") = nanobind::none(),
+         nanobind::arg("l") = nanobind::none(),
+         nanobind::arg("u") = nanobind::none(),
          nanobind::arg("update_preconditioner") = false,
-         nanobind::arg("rho") = nullopt,
-         nanobind::arg("mu_eq") = nullopt,
-         nanobind::arg("mu_in") = nullopt,
-         nanobind::arg("manual_minimal_H_eigenvalue") = nullopt)
+         nanobind::arg("rho") = nanobind::none(),
+         nanobind::arg("mu_eq") = nanobind::none(),
+         nanobind::arg("mu_in") = nanobind::none(),
+         nanobind::arg("manual_minimal_H_eigenvalue") = nanobind::none())
     .def("solve",
          static_cast<void (sparse::QP<T, I>::*)()>(&sparse::QP<T, I>::solve),
          "function used for solving the QP problem, using default parameters.")