diff --git a/autotest/t505_test.py b/autotest/t505_test.py
index 5bdc55ec49..1933116e4b 100644
--- a/autotest/t505_test.py
+++ b/autotest/t505_test.py
@@ -93,6 +93,7 @@ def np001():
     kwargs['xul'] = 20.5
     good_model = ModflowGwf(test_sim, modelname=model_name,
                             model_nam_file='{}.nam'.format(model_name),
+                            model_rel_path='model_folder',
                             **kwargs)
 
     # create simulation
diff --git a/flopy/mf6/mfmodel.py b/flopy/mf6/mfmodel.py
index 49e0d1cbef..2c322c4ff8 100644
--- a/flopy/mf6/mfmodel.py
+++ b/flopy/mf6/mfmodel.py
@@ -103,13 +103,13 @@ def __init__(self, simulation, model_type='gwf6', modelname='model',
         if model_nam_file is None:
             model_nam_file = '{}.nam'.format(modelname)
 
-        self.set_model_relative_path(model_rel_path)
         if add_to_simulation:
             self.structure = simulation.register_model(self, model_type,
                                                        modelname,
                                                        model_nam_file)
         else:
             self.structure = structure
+        self.set_model_relative_path(model_rel_path)
         self.exe_name = exe_name
         self.dimensions = modeldimensions.ModelDimensions(self.name,
                                                           self.simulation_data)