diff --git a/report_py3o/README.rst b/report_py3o/README.rst
index 11d1a5f4..0803f7ce 100644
--- a/report_py3o/README.rst
+++ b/report_py3o/README.rst
@@ -167,7 +167,7 @@ display_address(partner)
 formatLang(value, digits=None, date=False, date_time=False, grouping=True, monetary=False, dp=False, currency_obj=False)
     Return a formatted numeric, monetary, date or time value according to the context language and timezone
     (old implementation kept for compatibility and ease migration)
-o_format_lang(value, digits=None, grouping=True, monetary=False, dp=False, currency_obj=False, no_break_space=True)
+o_format_lang(value, lang_code=False, digits=None, grouping=True, monetary=False, dp=False, currency_obj=False, no_break_space=True)
     Return a formatted numeric or monetary value according to the context language and timezone
 o_format_date(value, lang_code=False, date_format=False)
     Return a formatted date or time value according to the context language and timezone
diff --git a/report_py3o/models/_py3o_parser_context.py b/report_py3o/models/_py3o_parser_context.py
index 2d60b6d7..c5b55951 100644
--- a/report_py3o/models/_py3o_parser_context.py
+++ b/report_py3o/models/_py3o_parser_context.py
@@ -49,11 +49,15 @@ class Py3oParserContext(object):
             'b64decode': b64decode,
         }
 
-    def _format_lang(self, value, digits=None, grouping=True,
+    def _format_lang(self, value, lang_code=False, digits=None, grouping=True,
                      monetary=False, dp=False, currency_obj=False,
                      no_break_space=True):
+        env = self._env
+        if lang_code:
+            context = dict(env.context, lang=lang_code)
+            env = env(context=context)
         formatted_value = misc.formatLang(
-            self._env, value, digits=digits, grouping=grouping,
+            env, value, digits=digits, grouping=grouping,
             monetary=monetary, dp=dp, currency_obj=currency_obj)
         if currency_obj and currency_obj.symbol and no_break_space:
             parts = []