diff --git a/_test/test_instrument_classes/test_IX_aperture.m b/_test/test_instrument_classes/test_IX_aperture.m
index 1fddd49dc..ac3faf252 100644
--- a/_test/test_instrument_classes/test_IX_aperture.m
+++ b/_test/test_instrument_classes/test_IX_aperture.m
@@ -7,27 +7,8 @@
         %--------------------------------------------------------------------------
         function self = test_IX_aperture (varargin)
             
+            self@TestCaseWithSave(varargin{:});
             test_files_folder = fileparts(mfilename('fullpath'));
-            if nargin> 0
-                is = ismember(varargin,'-save');
-                if any(is)
-                    if numel(is)>2
-                        error('HERBERT:test_IX_apperture:invalid_argument',...
-                            'the test can be called only with one or two parameters')
-                    elseif numel(is)==1
-                        filename = 'test_IX_aperture_output.mat';
-                    else
-                        filename = varargin{~is};
-                    end
-                    opt = '-save';
-                    params={opt,filename};
-                else
-                    params= varargin(1);
-                end
-            else
-                params= {'test_IX_aperture'};
-            end
-            self@TestCaseWithSave(params{:});
             self.home_folder = test_files_folder;
             %does nothing unless the constructor called with '-save' key
             self.save()
@@ -73,7 +54,7 @@ function test_aperture_array_prev_versions(obj)
             % 2x2 array example
             ap_arr = [IX_aperture('Ap0', 11, 0.2, 0.25), IX_aperture('Ap1', 121, 0.22, 0.225);...
                 IX_aperture('Ap3', 311, 0.23, 0.325), IX_aperture('Ap4', 114, 0.24, 0.245)];
-            sample_file_location = obj.home_folder;            
+            sample_file_location = obj.home_folder;
             if obj.save_output % prepare test data for the future.
                 % move test data to data folder manually
                 % run test_IX_apperture with -save option to obtain reference
@@ -102,8 +83,8 @@ function test_single_aperture_load_prev_versions(obj)
             ap = IX_aperture ('Ap0', 11, 0.2, 0.25);
             sample_files_location = obj.home_folder;
             if obj.save_output
-            % run test_IX_apperture with -save option to obtain reference
-            % files when changed to new class version                
+                % run test_IX_apperture with -save option to obtain reference
+                % files when changed to new class version
                 save_variables=true;
                 ver = ap.classVersion();
                 verstr = ['ver',num2str(ver)];