diff --git a/zuul.d/base.yaml b/zuul.d/base.yaml
index 880e64f..12408ea 100644
--- a/zuul.d/base.yaml
+++ b/zuul.d/base.yaml
@@ -110,9 +110,10 @@
       devstack_localrc:
         PHYSICAL_NETWORK: default
         CIRROS_VERSION: 0.5.1
-        IMAGE_URLS: https://cloud-images.ubuntu.com/releases/bionic/release/ubuntu-18.04-server-cloudimg-amd64.img
-        ADVANCED_IMAGE_NAME: ubuntu-18.04-server-cloudimg-amd64
-        ADVANCED_INSTANCE_TYPE: ntp_image_384M
+        IMAGE_URLS: https://cloud-images.ubuntu.com/minimal/releases/focal/release/ubuntu-20.04-minimal-cloudimg-amd64.img
+        ADVANCED_IMAGE_NAME: ubuntu-20.04-minimal-cloudimg-amd64
+        ADVANCED_INSTANCE_TYPE: ntp_image_256M
         ADVANCED_INSTANCE_USER: ubuntu
+        CUSTOMIZE_IMAGE: true
         BUILD_TIMEOUT: 784
       tempest_concurrency: 3  # out of 4