diff --git a/.automation.conf/tempest/tempest-ci-aio.overrides.conf b/.automation.conf/tempest/tempest-ci-aio.overrides.conf
index f40d52d53..cc7ef27cd 100644
--- a/.automation.conf/tempest/tempest-ci-aio.overrides.conf
+++ b/.automation.conf/tempest/tempest-ci-aio.overrides.conf
@@ -1 +1,3 @@
-# Blank file
+[openstack]
+# Use a StackHPC-built image without a default password.
+img_url=https://github.com/stackhpc/cirros/releases/download/20231206/cirros-d231206-x86_64-disk.img
diff --git a/.automation.conf/tempest/tempest-ci-multinode.overrides.conf b/.automation.conf/tempest/tempest-ci-multinode.overrides.conf
index 663b384df..ced9403f5 100644
--- a/.automation.conf/tempest/tempest-ci-multinode.overrides.conf
+++ b/.automation.conf/tempest/tempest-ci-multinode.overrides.conf
@@ -1,6 +1,9 @@
 [DEFAULT]
 openstack_client_http_timeout = 300
 
+[openstack]
+img_url=https://github.com/stackhpc/cirros/releases/download/20231206/cirros-d231206-x86_64-disk.img
+
 [auth]
 compute_quotas = cores:-1,ram:-1