diff --git a/ihatemoney/models.py b/ihatemoney/models.py
index 544558a8..a69da732 100644
--- a/ihatemoney/models.py
+++ b/ihatemoney/models.py
@@ -25,7 +25,7 @@ class Project(db.Model):
     contact_email = db.Column(db.String(128))
     members = db.relationship("Person", backref="project")
 
-    default_currency = "USD"
+    default_currency = db.Column(db.String(3))
 
     @property
     def _to_serialize(self):