diff --git a/swh/storage/cassandra/storage.py b/swh/storage/cassandra/storage.py
--- a/swh/storage/cassandra/storage.py
+++ b/swh/storage/cassandra/storage.py
@@ -938,12 +938,15 @@
     def _origin_visit_status_add(self, visit_status: OriginVisitStatus) -> None:
         """Add an origin visit status"""
         if visit_status.type is None:
-            origin_row = self._cql_runner.origin_visit_get_one(
+            visit_row = self._cql_runner.origin_visit_get_one(
                 visit_status.origin, visit_status.visit
             )
-            if origin_row is None:
-                raise StorageArgumentException(f"Unknown origin {visit_status.origin}")
-            visit_status = attr.evolve(visit_status, type=origin_row.type)
+            if visit_row is None:
+                raise StorageArgumentException(
+                    f"Unknown origin visit {visit_status.visit} "
+                    f"of origin {visit_status.origin}"
+                )
+            visit_status = attr.evolve(visit_status, type=visit_row.type)
 
         self.journal_writer.origin_visit_status_add([visit_status])
         self._cql_runner.origin_visit_status_add_one(
diff --git a/swh/storage/postgresql/storage.py b/swh/storage/postgresql/storage.py
--- a/swh/storage/postgresql/storage.py
+++ b/swh/storage/postgresql/storage.py
@@ -954,7 +954,11 @@
                 origin_visit = self.origin_visit_get_by(
                     visit_status.origin, visit_status.visit, db=db, cur=cur
                 )
-                assert origin_visit is not None
+                if origin_visit is None:
+                    raise StorageArgumentException(
+                        f"Unknown origin visit {visit_status.visit} "
+                        f"of origin {visit_status.origin}"
+                    )
 
                 origin_visit_status = attr.evolve(visit_status, type=origin_visit.type)
             else:
diff --git a/swh/storage/tests/storage_tests.py b/swh/storage/tests/storage_tests.py
--- a/swh/storage/tests/storage_tests.py
+++ b/swh/storage/tests/storage_tests.py
@@ -1606,6 +1606,33 @@
         assert actual_page.next_page_token is None
         assert actual_page.results == []
 
+    def test_origin_visit_status_add_unknown_type(self, swh_storage, sample_data):
+        ov = OriginVisit(
+            origin=sample_data.origin.url,
+            date=now(),
+            type=sample_data.type_visit1,
+            visit=42,
+        )
+        ovs = OriginVisitStatus(
+            origin=ov.origin,
+            visit=ov.visit,
+            date=now(),
+            status="created",
+            snapshot=None,
+        )
+
+        with pytest.raises(StorageArgumentException):
+            swh_storage.origin_visit_status_add([ovs])
+
+        swh_storage.origin_add([sample_data.origin])
+
+        with pytest.raises(StorageArgumentException):
+            swh_storage.origin_visit_status_add([ovs])
+
+        swh_storage.origin_visit_add([ov])
+
+        swh_storage.origin_visit_status_add([ovs])
+
     def test_origin_visit_status_get_all(self, swh_storage, sample_data):
         origin = sample_data.origin
         swh_storage.origin_add([origin])