diff --git a/smash/web/models/study_subject.py b/smash/web/models/study_subject.py
index cc8b74afacf1edc12b820407476707a7e2d610da..3854138909c993a2dbd98168dffd849b6fa48d97 100644
--- a/smash/web/models/study_subject.py
+++ b/smash/web/models/study_subject.py
@@ -163,7 +163,7 @@ class StudySubject(models.Model):
         matches, reminder = [], []
         for part in parts:
             chunks = part.strip().split('-')
-            if chunks == 2:
+            if len(chunks) == 2:
               letter, number = chunks
               tupl = (letter, int(number))
             else: