diff --git a/swh/deposit/loader/checker.py b/swh/deposit/loader/checker.py
--- a/swh/deposit/loader/checker.py
+++ b/swh/deposit/loader/checker.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2017-2019  The Software Heritage developers
+# Copyright (C) 2017-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -39,10 +39,13 @@
     def check(self, collection: str, deposit_id: str) -> Mapping[str, str]:
         status = None
         deposit_check_url = f"/{collection}/{deposit_id}/check/"
+        logger.debug("deposit-check-url: %s", deposit_check_url)
         try:
             r = self.client.check(deposit_check_url)
+            logger.debug("Check result: %s", r)
             status = "eventful" if r == "verified" else "failed"
         except Exception:
-            logger.exception("Failure during check on '%s'" % (deposit_check_url,))
+            logger.exception("Failure during check on '%s'", deposit_check_url)
             status = "failed"
+        logger.debug("Check status: %s", status)
         return {"status": status}
diff --git a/swh/deposit/tests/loader/test_tasks.py b/swh/deposit/tests/loader/test_tasks.py
--- a/swh/deposit/tests/loader/test_tasks.py
+++ b/swh/deposit/tests/loader/test_tasks.py
@@ -1,21 +1,69 @@
-# Copyright (C) 2018-2019  The Software Heritage developers
+# Copyright (C) 2018-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from unittest.mock import patch
+import pytest
 
 
-@patch("swh.deposit.loader.checker.DepositChecker.check")
-def test_deposit_check(checker, swh_config, swh_app, celery_session_worker):
-    checker.return_value = {"status": "uneventful"}
+@pytest.mark.db
+def test_deposit_check_eventful(mocker, swh_config, swh_app, celery_session_worker):
+    """Successful check should make the check succeed
 
+    """
+    client = mocker.patch("swh.deposit.loader.checker.PrivateApiDepositClient.check")
+    client.return_value = "verified"
+
+    collection = "collection"
+    deposit_id = 42
+    res = swh_app.send_task(
+        "swh.deposit.loader.tasks.ChecksDepositTsk", args=[collection, deposit_id]
+    )
+    assert res
+    res.wait()
+    assert res.successful()
+
+    assert res.result == {"status": "eventful"}
+    client.assert_called_once_with(f"/{collection}/{deposit_id}/check/")
+
+
+@pytest.mark.db
+def test_deposit_check_failure(mocker, swh_config, swh_app, celery_session_worker):
+    """Unverified check status should make the check fail
+
+    """
+    client = mocker.patch("swh.deposit.loader.checker.PrivateApiDepositClient.check")
+    client.return_value = "not-verified"  # will make the status "failed"
+
+    collection = "collec"
+    deposit_id = 666
+    res = swh_app.send_task(
+        "swh.deposit.loader.tasks.ChecksDepositTsk", args=[collection, deposit_id]
+    )
+    assert res
+    res.wait()
+    assert res.successful()
+
+    assert res.result == {"status": "failed"}
+    client.assert_called_once_with(f"/{collection}/{deposit_id}/check/")
+
+
+@pytest.mark.db
+def test_deposit_check_3(mocker, swh_config, swh_app, celery_session_worker):
+    """Unexpected failures should fail the check
+
+    """
+    client = mocker.patch("swh.deposit.loader.checker.PrivateApiDepositClient.check")
+    client.side_effect = ValueError("unexpected failure will make it fail")
+
+    collection = "another-collection"
+    deposit_id = 999
     res = swh_app.send_task(
-        "swh.deposit.loader.tasks.ChecksDepositTsk", args=["collection", 42]
+        "swh.deposit.loader.tasks.ChecksDepositTsk", args=[collection, deposit_id]
     )
     assert res
     res.wait()
     assert res.successful()
 
-    assert res.result == {"status": "uneventful"}
-    checker.assert_called_once_with("collection", 42)
+    assert res.result == {"status": "failed"}
+    client.assert_called_once_with(f"/{collection}/{deposit_id}/check/")