diff --git a/aprendizations/serve.py b/aprendizations/serve.py
index ae97d60..53c25ad 100644
--- a/aprendizations/serve.py
+++ b/aprendizations/serve.py
@@ -283,6 +283,7 @@ class QuestionHandler(BaseHandler):
         logger.debug('[QuestionHandler.post]')
         user = self.current_user
         answer = self.get_body_arguments('answer')  # list
+        logger.debug(f'user = {user}, answer = {answer}')
 
         # --- check if browser opened different questions simultaneously
         answer_qid = self.get_body_arguments('qid')[0]
@@ -309,6 +310,8 @@ class QuestionHandler(BaseHandler):
             ans = None
         elif qtype != 'checkbox':   # radio, text, textarea, ...
             ans = answer[0]
+        else:
+            ans = answer
 
         # --- check answer (nonblocking) and get corrected question and action
         q, action = await self.learn.check_answer(user, ans)
--
libgit2 0.21.2