diff --git a/python/src/core/domains/ellipsoid/codac2_py_Ellipsoid.cpp b/python/src/core/domains/ellipsoid/codac2_py_Ellipsoid.cpp
index e1784a10..404f2034 100644
--- a/python/src/core/domains/ellipsoid/codac2_py_Ellipsoid.cpp
+++ b/python/src/core/domains/ellipsoid/codac2_py_Ellipsoid.cpp
@@ -13,6 +13,7 @@
 #include <pybind11/stl.h>
 #include <codac2_Ellipsoid.h>
 #include "codac2_py_Ellipsoid_docs.h" // Generated file from Doxygen XML (doxygen2docstring.py):
+#include "codac2_py_AnalyticFunction.h"
 
 using namespace std;
 using namespace codac2;
@@ -80,11 +81,17 @@ void export_Ellipsoid(py::module& m)
       ELLIPSOID_UNRELIABLE_LINEAR_MAPPING_CONST_ELLIPSOID_REF_CONST_MATRIX_REF_CONST_VECTOR_REF,
       "e"_a, "A"_a, "b"_a)
 
-    .def("nonlinear_mapping_", (Ellipsoid (*)(const Ellipsoid&,const AnalyticFunction<VectorOpValue>&))&codac2::nonlinear_mapping,
+    .def("nonlinear_mapping", [](const Ellipsoid& e, py::object f)
+        {
+          return nonlinear_mapping(e, pyobject_to_AnalyticFunction(f));
+        },
       ELLIPSOID_NONLINEAR_MAPPING_CONST_ELLIPSOID_REF_CONST_ANALYTICFUNCTION_VECTOROPVALUE_REF,
       "e"_a, "f"_a)
 
-    .def("nonlinear_mapping_", (Ellipsoid (*)(const Ellipsoid&,const AnalyticFunction<VectorOpValue>&,const Vector&,const Vector&))&codac2::nonlinear_mapping,
+    .def("nonlinear_mapping", [](const Ellipsoid& e, py::object f, const Vector &trig, const Vector &q)
+        {
+          return nonlinear_mapping(e, pyobject_to_AnalyticFunction(f), trig, q);
+        },
       ELLIPSOID_NONLINEAR_MAPPING_CONST_ELLIPSOID_REF_CONST_ANALYTICFUNCTION_VECTOROPVALUE_REF_CONST_VECTOR_REF_CONST_VECTOR_REF,
       "e"_a, "f"_a, "trig"_a, "q"_a)
 
diff --git a/python/src/core/functions/analytic/codac2_py_AnalyticFunction.h b/python/src/core/functions/analytic/codac2_py_AnalyticFunction.h
index 9dd8c75b..9647582b 100644
--- a/python/src/core/functions/analytic/codac2_py_AnalyticFunction.h
+++ b/python/src/core/functions/analytic/codac2_py_AnalyticFunction.h
@@ -25,6 +25,22 @@ using namespace codac2;
 namespace py = pybind11;
 using namespace pybind11::literals;
 
+inline AnalyticFunction<VectorOpValue> pyobject_to_AnalyticFunction(py::object f)
+{
+  if(py::isinstance<AnalyticFunction<VectorOpValue>>(f))
+    return f.cast<AnalyticFunction<VectorOpValue>>();
+
+  else
+  {
+    // Trying to extract an AnalyticFunction<VectorOpValue>
+    // from the python wrapper 'AnalyticFunction'
+    py::object f_ = f.attr("f");
+    if(!py::isinstance<AnalyticFunction<VectorOpValue>>(f_))
+      assert_release("invalid argument: AnalyticFunction<VectorOpValue> expected");
+    return f_.cast<AnalyticFunction<VectorOpValue>>();
+  }
+}
+
 #define bind_(exported, op_name, op, doc) \
   \
   exported \