diff --git a/zaza/openstack/charm_tests/glance_simplestreams_sync/setup.py b/zaza/openstack/charm_tests/glance_simplestreams_sync/setup.py
index 06e172d..ec6107b 100644
--- a/zaza/openstack/charm_tests/glance_simplestreams_sync/setup.py
+++ b/zaza/openstack/charm_tests/glance_simplestreams_sync/setup.py
@@ -17,6 +17,7 @@
 """Code for configuring glance-simplestreams-sync."""
 
 import logging
+import tenacity
 
 import zaza.model as zaza_model
 import zaza.openstack.utilities.generic as generic_utils
@@ -30,11 +31,17 @@ def sync_images():
     deployment.
     """
     logging.info("Synchronising images using glance-simplestreams-sync")
-    generic_utils.assertActionRanOK(
-        zaza_model.run_action_on_leader(
-            "glance-simplestreams-sync",
-            "sync-images",
-            raise_on_failure=True,
-            action_params={},
-        )
-    )
+    for attempt in tenacity.Retrying(
+            stop=tenacity.stop_after_attempt(3),
+            wait=tenacity.wait_exponential(
+                multiplier=1, min=2, max=10),
+            reraise=True):
+        with attempt:
+            generic_utils.assertActionRanOK(
+                zaza_model.run_action_on_leader(
+                    "glance-simplestreams-sync",
+                    "sync-images",
+                    raise_on_failure=True,
+                    action_params={},
+                )
+            )
diff --git a/zaza/openstack/charm_tests/policyd/tests.py b/zaza/openstack/charm_tests/policyd/tests.py
index 4722755..a87f2ef 100644
--- a/zaza/openstack/charm_tests/policyd/tests.py
+++ b/zaza/openstack/charm_tests/policyd/tests.py
@@ -401,9 +401,10 @@ class BasePolicydSpecialization(PolicydTest,
     def test_003_test_override_is_observed(self):
         """Test that the override is observed by the underlying service."""
         if (openstack_utils.get_os_release() <
-                openstack_utils.get_os_release('groovy_victoria')):
+                openstack_utils.get_os_release('xenial_queens')):
             raise unittest.SkipTest(
-                "Test skipped until Bug #1880959 is fix released")
+                "Test skipped because bug #1880959 won't be fixed for "
+                "releases older than Queens")
         if self._test_name is None:
             logging.info("Doing policyd override for {}"
                          .format(self._service_name))
@@ -571,6 +572,13 @@ class GlanceTests(BasePolicydSpecialization):
         super(GlanceTests, cls).setUpClass(application_name="glance")
         cls.application_name = "glance"
 
+    # NOTE(lourot): Same as NeutronApiTests. There is a race between the glance
+    # charm signalling its readiness and the service actually being ready to
+    # serve requests. The test will fail intermittently unless we gracefully
+    # accept this.
+    # Issue: openstack-charmers/zaza-openstack-tests#578
+    @tenacity.retry(wait=tenacity.wait_fixed(1),
+                    reraise=True, stop=tenacity.stop_after_delay(8))
     def get_client_and_attempt_operation(self, ip):
         """Attempt to list the images as a policyd override.
 
diff --git a/zaza/openstack/charm_tests/trilio/tests.py b/zaza/openstack/charm_tests/trilio/tests.py
index 5072b29..64239ae 100644
--- a/zaza/openstack/charm_tests/trilio/tests.py
+++ b/zaza/openstack/charm_tests/trilio/tests.py
@@ -440,7 +440,7 @@ class TrilioGhostNFSShareTest(TrilioBaseTest):
         )
 
 
-class TrilioWLMTest(TrilioGhostNFSShareTest):
+class TrilioWLMBaseTest(TrilioBaseTest):
     """Tests for Trilio Workload Manager charm."""
 
     conf_file = "/etc/workloadmgr/workloadmgr.conf"
@@ -478,3 +478,11 @@ class TrilioDataMoverNFSTest(TrilioDataMoverBaseTest, TrilioGhostNFSShareTest):
 
 class TrilioDataMoverS3Test(TrilioDataMoverBaseTest):
     """Tests for Trilio Data Mover charm backed by S3."""
+
+
+class TrilioWLMNFSTest(TrilioWLMBaseTest, TrilioGhostNFSShareTest):
+    """Tests for Trilio WLM charm backed by NFS."""
+
+
+class TrilioWLMS3Test(TrilioWLMBaseTest):
+    """Tests for Trilio WLM charm backed by S3."""