diff --git a/jenkins/jobs/magnum.yaml b/jenkins/jobs/magnum.yaml
index 1d160f9206..3417b8d4b4 100644
--- a/jenkins/jobs/magnum.yaml
+++ b/jenkins/jobs/magnum.yaml
@@ -109,8 +109,6 @@
 
           DIB_ELEMENTS=./openstack/diskimage-builder/elements
 
-          export DIB_IMAGE_SIZE=2.2
-
           if [ "{image-name}" == "ubuntu-mesos" ]; then
               TRIPLEO_ELEMENTS=./openstack/tripleo-image-elements/elements
               HEAT_ELEMENTS=./openstack/heat-templates/hot/software-config/elements
@@ -121,6 +119,8 @@
 
               export DIB_RELEASE=trusty
 
+              export DIB_IMAGE_SIZE=2.2
+
               disk-image-create ubuntu vm docker mesos \
                 os-collect-config os-refresh-config os-apply-config \
                 heat-config heat-config-script -o $WORKSPACE/{image-name}.qcow2
@@ -133,6 +133,8 @@
 
               export DIB_RELEASE="25"
 
+              export DIB_IMAGE_SIZE=2.5
+
               export FEDORA_ATOMIC_TREE_URL="https://kojipkgs.fedoraproject.org/atomic/25/"
               export FEDORA_ATOMIC_TREE_REF="8b15e9b988b4b02f4cb8b39bdd63d182ab7004a8926ecdac6314ee5c7ffa646b"