diff --git a/tests/test_load.py b/tests/test_load.py
index da8bc92..b39f673 100644
--- a/tests/test_load.py
+++ b/tests/test_load.py
@@ -1,7 +1,8 @@
 from .custom import CustomOption
 
 from pathlib import Path
-from os import getcwd, listdir, environ, makedirs
+from os import getcwd, listdir, makedirs
+import os
 from os.path import isfile, join, isdir, dirname
 from pathlib import Path
 from json import load, dump
@@ -23,7 +24,7 @@ dico_dirs = Path('../rougail/tests/dictionaries')
 #test_ok = [dico_dirs / env_test_folder]
 
 #let's save the original environment
-save = environ.copy()
+save = os.environ.copy()
 
 test_ok = set()
 excludes = set()
@@ -37,7 +38,6 @@ test_ok = list(test_ok)
 test_ok.sort()
 
 
-
 @fixture(scope="module", params=test_ok)
 def test_dir(request):
     return request.param
@@ -76,13 +76,14 @@ def test_dictionaries_warning(test_dir):
                                               user_datas=user_datas,
                                               )
     environment.run()
-    # expected output
+    #expected output
     with open(Path('tests') / 'envvars' / current_dirname /  'makedict' / 'all.env') as json_file:
         expected = load(json_file)
     # here is the effective test
+    config_dict = dict(option_value(config.value.get()))
     assert  expected == config_dict
     #teardown: set the original environement again
-    environ = save
+    os.environ = save.copy()
 
 
 def populate(dest_dir, rougailconfig):
@@ -97,13 +98,12 @@ def populate(dest_dir, rougailconfig):
                 root_config = config.unrestraint
             else:
                 root_config = config.unrestraint.value.mandatory()
-            values = ['ROUGAIL_' + variable.path().upper() + '="' + get_value(variable) + '"' for variable in get_variables(root_config)]
+            values = ['ROUGAIL_' + variable.path().upper() + '="' + "" if get_value(variable) is None else get_value(variable) + '"' for variable in get_variables(root_config)]
         if not environment_file.is_file():
             with environment_file.open('w') as envfh:
                 envfh.write('\n'.join(values) + '\n')
         if  not makedict_file.is_file():
             with makedict_file.open('w') as envfh:
-                #envfh.write('\n'.join(values) + '\n')
                 config_dict = dict(option_value(config.value.get()))
                 dump(config_dict, envfh, indent=4)
                 envfh.write('\n')