diff --git a/swh/model/model.py b/swh/model/model.py
--- a/swh/model/model.py
+++ b/swh/model/model.py
@@ -102,7 +102,7 @@
 class OriginVisit(BaseModel):
     """Represents a visit of an origin at a given point in time, by a
     SWH loader."""
-    origin = attr.ib(type=Origin)
+    origin = attr.ib(type=str)
     date = attr.ib(type=datetime.datetime)
     status = attr.ib(
         type=str,