diff --git a/tests/submodels/test_dfba.py b/tests/submodels/test_dfba.py
index 431ca91a..69978f4b 100644
--- a/tests/submodels/test_dfba.py
+++ b/tests/submodels/test_dfba.py
@@ -705,7 +705,6 @@ def test_run_fba_solver(self):
                                    'm2[c]': -12,
                                    'm3[c]': 10}
         self.check_expected_solution(dfba_submodel_2, 10, expected_adjustments_IV)
-        dfba_submodel_2.time_step = 1
 
         TEST_NAME = "V: Modify II by scaling the coefficients of objective function's terms by 10"
         self.dfba_submodel_options['dfba_coef_scale_factor'] = 10.
diff --git a/wc_sim/submodels/dfba.py b/wc_sim/submodels/dfba.py
index 1dac4072..ea8deb59 100644
--- a/wc_sim/submodels/dfba.py
+++ b/wc_sim/submodels/dfba.py
@@ -671,9 +671,9 @@ def unscale_conv_opt_solution(self, dfba_bound_scale_factor=None, dfba_coef_scal
         if dfba_coef_scale_factor is None:
             dfba_coef_scale_factor = self.dfba_solver_options['dfba_coef_scale_factor']
 
-        self._optimal_obj_func_value /= (dfba_coef_scale_factor * dfba_bound_scale_factor)
         for rxn_variable in self._conv_model.variables:
             self.reaction_fluxes[rxn_variable.name] /= dfba_bound_scale_factor
+        self._optimal_obj_func_value /= (dfba_coef_scale_factor * dfba_bound_scale_factor)
 
     def save_fba_solution(self, conv_opt_model, conv_opt_solution):
         """ Assign a FBA solution to local variables