diff --git a/longs/models.py b/longs/models.py
index cd596a49..efde1dd7 100644
--- a/longs/models.py
+++ b/longs/models.py
@@ -129,6 +129,9 @@ class Long(models.Model):
 
     question_json_id = models.IntegerField(default=1, help_text="Auto incrementing json creation number")
 
+
+    sorted_series = SortedManyToManyField("LongSeries")
+
     #question_file = models.FileField(upload_to=question_file_directory_path, blank=True, null=True)
 
     def get_absolute_url(self):