diff --git a/pythonfmu/csvbuilder.py b/pythonfmu/csvbuilder.py
index c36c513..8cfa1ce 100644
--- a/pythonfmu/csvbuilder.py
+++ b/pythonfmu/csvbuilder.py
@@ -150,7 +150,7 @@ def find_indices(self, t, dt):
                     self.next_index += 1
                     next_t = self.times[self.next_index]
 
-    def setup_experiment(self, start_time: float):
+    def setup_experiment(self, start_time: float, stop_time, tolerance):
         self.current_time = start_time
         self.find_indices(start_time, 0)
 
diff --git a/pythonfmu/fmi2slave.py b/pythonfmu/fmi2slave.py
index 6657b7f..1599142 100644
--- a/pythonfmu/fmi2slave.py
+++ b/pythonfmu/fmi2slave.py
@@ -172,7 +172,7 @@ def register_variable(self, var: ScalarVariable, nested: bool = True):
         if var.setter is None and hasattr(owner, var.local_name) and var.variability != Fmi2Variability.constant:
             var.setter = lambda v: setattr(owner, var.local_name, v)
 
-    def setup_experiment(self, start_time: float):
+    def setup_experiment(self, start_time: float, stop_time: Optional[float], tolerance: Optional[float]):
         pass
 
     def enter_initialization_mode(self):
diff --git a/pythonfmu/pythonfmu-export/src/pythonfmu/PySlaveInstance.cpp b/pythonfmu/pythonfmu-export/src/pythonfmu/PySlaveInstance.cpp
index 06045ec..f05c866 100644
--- a/pythonfmu/pythonfmu-export/src/pythonfmu/PySlaveInstance.cpp
+++ b/pythonfmu/pythonfmu-export/src/pythonfmu/PySlaveInstance.cpp
@@ -226,8 +226,15 @@ class PySlaveInstance : public SlaveInstance
 
     void SetupExperiment(double startTime, std::optional<double> stop, std::optional<double> tolerance) override
     {
-        py_safe_run([this, startTime](PyGILState_STATE gilState) {
-            auto f = PyObject_CallMethod(pInstance_, "setup_experiment", "(d)", startTime);
+        py_safe_run([this, startTime, stop, tolerance](PyGILState_STATE gilState) {
+            PyObject* pyStop = stop ? Py_BuildValue("d", *stop) : (Py_INCREF(Py_None), Py_None);
+            PyObject* pyTol = tolerance ? Py_BuildValue("d", *tolerance) : (Py_INCREF(Py_None), Py_None);
+
+            auto f = PyObject_CallMethod(pInstance_, "setup_experiment", "(dOO)", startTime, pyStop, pyTol);
+
+            Py_DECREF(pyStop);
+            Py_DECREF(pyTol);
+
             if (f == nullptr) {
                 handle_py_exception("[setupExperiment] PyObject_CallMethod", gilState);
             }