diff --git a/addons/survey/models/survey_user.py b/addons/survey/models/survey_user.py
index a9a8bc57b9f..4213e0b1662 100644
--- a/addons/survey/models/survey_user.py
+++ b/addons/survey/models/survey_user.py
@@ -360,7 +360,7 @@ class SurveyUserInput(models.Model):
     def _choice_question_answer_result(self, user_input_lines, question_correct_suggested_answers):
         correct_user_input_lines = user_input_lines.filtered(lambda line: line.answer_is_correct and not line.skipped).mapped('suggested_answer_id')
         incorrect_user_input_lines = user_input_lines.filtered(lambda line: not line.answer_is_correct and not line.skipped)
-        if correct_user_input_lines == question_correct_suggested_answers:
+        if question_correct_suggested_answers and correct_user_input_lines == question_correct_suggested_answers:
             return 'correct'
         elif correct_user_input_lines and correct_user_input_lines < question_correct_suggested_answers:
             return 'partial'