diff --git a/requirements-swh.txt b/requirements-swh.txt
--- a/requirements-swh.txt
+++ b/requirements-swh.txt
@@ -1,4 +1,4 @@
 # Add here internal Software Heritage dependencies, one per line.
 swh.core[db,http] >= 0.14
-swh.model
+swh.model >= 2.6.1
 swh.storage
diff --git a/swh/provenance/model.py b/swh/provenance/model.py
--- a/swh/provenance/model.py
+++ b/swh/provenance/model.py
@@ -81,19 +81,19 @@
 
     def parents(self, archive: ArchiveInterface):
         if self._parents is None:
-            revision = archive.revision_get([self.id])
+            revision = list(archive.revision_get([self.id]))
             if revision:
-                self._parents = list(revision)[0].parents
+                self._parents = revision[0].parents
         if self._parents and not self._nodes:
             self._nodes = [
                 RevisionEntry(
                     id=rev.id,
                     root=rev.directory,
-                    date=rev.date,
+                    date=rev.date.to_datetime(),
                     parents=rev.parents,
                 )
                 for rev in archive.revision_get(self._parents)
-                if rev
+                if rev is not None and rev.date is not None
             ]
         yield from self._nodes