diff --git a/tiramisu/i18n.py b/tiramisu/i18n.py
index 6947b39..1f624e8 100644
--- a/tiramisu/i18n.py
+++ b/tiramisu/i18n.py
@@ -18,10 +18,12 @@
 # the rough gus of pypy: pypy: http://codespeak.net/svn/pypy/dist/pypy/config/
 # the whole pypy projet is under MIT licence
 "internationalisation utilities"
+from .log import log
+
 from gettext import translation, NullTranslations
 from platform import system
 from pkg_resources import resource_filename
-from .log import log
+from os import environ
 
 
 DEFAULT = 'en'
@@ -35,22 +37,25 @@ def get_translation() -> str:
     app_name = __name__[:-5]
     translations_path = resource_filename(app_name, 'locale')
 
-    if 'Windows' in system():
-        import ctypes
-        from locale import windows_locale
-        default_locale = windows_locale[ctypes.windll.kernel32.GetUserDefaultUILanguage()]
+    if 'TIRAMISU_LOCALE' in environ:
+        user_locale = environ['TIRAMISU_LOCALE']
     else:
-        from locale import getdefaultlocale
-        default_locale = getdefaultlocale()
-    if default_locale and isinstance(default_locale, tuple):
-        if default_locale[0] is not None:
-            user_locale = default_locale[0][:2]
+        if 'Windows' in system():
+            import ctypes
+            from locale import windows_locale
+            default_locale = windows_locale[ctypes.windll.kernel32.GetUserDefaultUILanguage()]
+        else:
+            from locale import getdefaultlocale
+            default_locale = getdefaultlocale()
+        if default_locale and isinstance(default_locale, tuple):
+            if default_locale[0] is not None:
+                user_locale = default_locale[0][:2]
+            else:
+                user_locale = DEFAULT
+        elif default_locale:
+            user_locale = default_locale[:2]
         else:
             user_locale = DEFAULT
-    elif default_locale:
-        user_locale = default_locale[:2]
-    else:
-        user_locale = DEFAULT
     try:
         trans = translation(domain=app_name,
                             localedir=translations_path,