diff --git a/addons/survey/models/survey.py b/addons/survey/models/survey.py
index d4d20c915eb..e40e8d29235 100644
--- a/addons/survey/models/survey.py
+++ b/addons/survey/models/survey.py
@@ -637,7 +637,7 @@ class SurveyQuestion(models.Model):
             if self.comments_allowed:
                 comment_answer = answer_candidates.pop(("%s_%s" % (answer_tag, 'comment')), '').strip()
             # Preventing answers with blank value
-            if all([True if not answer.strip() else False for answer in answer_candidates.values()]):
+            if all([True if not answer.strip() else False for answer in answer_candidates.values()]) and answer_candidates:
                 errors.update({answer_tag: self.constr_error_msg})
             # There is no answer neither comments (if comments count as answer)
             if not answer_candidates and self.comment_count_as_answer and (not comment_flag or not comment_answer):