diff --git a/swh/core/db/tests/test_db.py b/swh/core/db/tests/test_db.py
--- a/swh/core/db/tests/test_db.py
+++ b/swh/core/db/tests/test_db.py
@@ -182,7 +182,7 @@
         TestIntEnum.foo,
         strategies.sampled_from(TestIntEnum),
         in_wrapper=int,
-        out_converter=TestIntEnum,
+        out_converter=lambda x: TestIntEnum(x),  # lambda needed by mypy
     ),
     Field("uuid", "uuid", uuid.uuid4(), strategies.uuids()),
     Field(
diff --git a/tox.ini b/tox.ini
--- a/tox.ini
+++ b/tox.ini
@@ -46,7 +46,7 @@
   db
   http
 deps =
-  mypy==0.920
+  mypy==0.942
 commands =
   mypy swh