diff --git a/flashcards/models.py b/flashcards/models.py
index b24a459..193af29 100644
--- a/flashcards/models.py
+++ b/flashcards/models.py
@@ -143,6 +143,11 @@ class UserFlashcard(Model):
     pulled = DateTimeField(auto_now_add=True, help_text="When the user pulled the card")
     flashcard = ForeignKey('Flashcard')
 
+    def get_mask(self):
+        if self.mask is None:
+            return self.flashcard.mask
+        return self.mask
+
     class Meta:
         # There can be at most one UserFlashcard for each User and Flashcard
         unique_together = (('user', 'flashcard'),)
diff --git a/flashcards/views.py b/flashcards/views.py
index 93c2930..624ac61 100644
--- a/flashcards/views.py
+++ b/flashcards/views.py
@@ -342,6 +342,7 @@ class FlashcardViewSet(GenericViewSet, CreateModelMixin, RetrieveModelMixin):
         new_flashcard = flashcard.edit(user, new_flashcard)
         return Response(FlashcardSerializer(new_flashcard).data, status=HTTP_200_OK)
 
+
 class UserFlashcardQuizViewSet(GenericViewSet, CreateModelMixin, UpdateModelMixin):
     permission_classes = [IsAuthenticated, IsFlashcardReviewer]
     queryset = UserFlashcardQuiz.objects.all()
@@ -373,11 +374,10 @@ class UserFlashcardQuizViewSet(GenericViewSet, CreateModelMixin, UpdateModelMixi
             raise ValidationError("No matching flashcard found in your decks")
 
         user_flashcard = user_flashcard_filter.order_by('?').first()
-        mask = user_flashcard.mask.get_random_blank()
+        mask = user_flashcard.get_mask().get_random_blank()
         user_flashcard_quiz = UserFlashcardQuiz(user_flashcard=user_flashcard,
                                                 blanked_word=user_flashcard.flashcard.text[slice(*mask)])
         user_flashcard_quiz.save()
-        assert user_flashcard_quiz is not None
         response = QuizResponseSerializer(instance=user_flashcard_quiz, mask=mask)
         return Response(response.data, status=HTTP_200_OK)