diff --git a/test-requirements.txt b/test-requirements.txt
index 0c35ba9..af976b3 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -37,7 +37,8 @@ git+https://github.com/openstack-charmers/zaza.git@stable/yoga#egg=zaza
 git+https://github.com/openstack-charmers/zaza-openstack-tests.git@stable/yoga#egg=zaza.openstack
 
 # Needed for charm-glance:
-git+https://opendev.org/openstack/tempest.git#egg=tempest;python_version>='3.6'
+git+https://opendev.org/openstack/tempest.git#egg=tempest;python_version>='3.8'
+tempest<31.0.0;python_version<'3.8' and python_version>='3.6'
 tempest<24.0.0;python_version<'3.6'
 
 croniter            # needed for charm-rabbitmq-server unit tests
diff --git a/tests/bundles/focal-xena.yaml b/tests/bundles/focal-xena.yaml
index c80055b..f608ee1 100644
--- a/tests/bundles/focal-xena.yaml
+++ b/tests/bundles/focal-xena.yaml
@@ -1,3 +1,5 @@
+local_overlay_enabled: False
+
 variables:
   openstack-origin: &openstack-origin cloud:focal-xena
 
@@ -28,13 +30,13 @@ applications:
 
   keystone-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   cinder-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   glance-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
 
   mysql-innodb-cluster:
     charm: ch:mysql-innodb-cluster
@@ -45,7 +47,7 @@ applications:
       - '0'
       - '1'
       - '2'
-    channel: latest/edge
+    channel: 8.0/edge
 
   keystone:
     charm: ch:keystone
@@ -61,7 +63,7 @@ applications:
     num_units: 1
     to:
       - '4'
-    channel: latest/edge
+    channel: 3.9/edge
 
   ceph-mon:
     charm: ch:ceph-mon
diff --git a/tests/bundles/focal-yoga.yaml b/tests/bundles/focal-yoga.yaml
index 13c65f0..1bf66aa 100644
--- a/tests/bundles/focal-yoga.yaml
+++ b/tests/bundles/focal-yoga.yaml
@@ -1,3 +1,5 @@
+local_overlay_enabled: False
+
 variables:
   openstack-origin: &openstack-origin cloud:focal-yoga
 
@@ -28,13 +30,13 @@ applications:
 
   keystone-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   cinder-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   glance-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
 
   mysql-innodb-cluster:
     charm: ch:mysql-innodb-cluster
@@ -45,7 +47,7 @@ applications:
       - '0'
       - '1'
       - '2'
-    channel: latest/edge
+    channel: 8.0/edge
 
   keystone:
     charm: ch:keystone
@@ -61,7 +63,7 @@ applications:
     num_units: 1
     to:
       - '4'
-    channel: latest/edge
+    channel: 3.9/edge
 
   ceph-mon:
     charm: ch:ceph-mon
diff --git a/tests/bundles/impish-xena.yaml b/tests/bundles/impish-xena.yaml
index 7691d95..eb80b73 100644
--- a/tests/bundles/impish-xena.yaml
+++ b/tests/bundles/impish-xena.yaml
@@ -1,3 +1,5 @@
+local_overlay_enabled: False
+
 variables:
   openstack-origin: &openstack-origin distro
 
@@ -28,13 +30,13 @@ applications:
 
   keystone-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   cinder-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   glance-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
 
   mysql-innodb-cluster:
     charm: ch:mysql-innodb-cluster
@@ -45,7 +47,7 @@ applications:
       - '0'
       - '1'
       - '2'
-    channel: latest/edge
+    channel: 8.0/edge
 
   keystone:
     charm: ch:keystone
@@ -61,7 +63,7 @@ applications:
     num_units: 1
     to:
       - '4'
-    channel: latest/edge
+    channel: 3.9/edge
 
   ceph-mon:
     charm: ch:ceph-mon
diff --git a/tests/bundles/jammy-yoga.yaml b/tests/bundles/jammy-yoga.yaml
index 58874e1..95d2ec1 100644
--- a/tests/bundles/jammy-yoga.yaml
+++ b/tests/bundles/jammy-yoga.yaml
@@ -1,3 +1,5 @@
+local_overlay_enabled: False
+
 variables:
   openstack-origin: &openstack-origin distro
 
@@ -28,13 +30,13 @@ applications:
 
   keystone-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   cinder-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
   glance-mysql-router:
     charm: ch:mysql-router
-    channel: latest/edge
+    channel: 8.0/edge
 
   mysql-innodb-cluster:
     charm: ch:mysql-innodb-cluster
@@ -45,7 +47,7 @@ applications:
       - '0'
       - '1'
       - '2'
-    channel: latest/edge
+    channel: 8.0/edge
 
   keystone:
     charm: ch:keystone
@@ -61,7 +63,7 @@ applications:
     num_units: 1
     to:
       - '4'
-    channel: latest/edge
+    channel: 3.9/edge
 
   ceph-mon:
     charm: ch:ceph-mon