diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9c51004e7601995b2297b15b7e3a97982c00baf9..765466271774540c403eecae2c65849d834f2c85 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -243,7 +243,7 @@ deploy_knightly:
       fi
     - |
       SERVER_TO_BE_DELETE=($(openstack server list --name $OOD_INSTANCE_NAME --sort-column Image --sort-descending -f value -c ID | sed -n $(($NUM_SERVER_TO_KEEP+1))',$p'))
-      IMAGE_TO_BE_DELETE=($(openstack image list --sort-column Name --sort-descending -f value -c Name | grep -P '^ood-\d{8}$' | sed -n $(($NUM_IMAGE_TO_KEEP+1))',$p'))
+      IMAGE_TO_BE_DELETE=($(openstack image list --sort-column Name --sort-descending -f value -c Name -c ID | grep -P ' ood-\d{8}$' | sed -n $(($NUM_IMAGE_TO_KEEP+1))',$p' | awk '{print $1}'))
       for svr in ${SERVER_TO_BE_DELETE[@]}; do
         openstack server delete ${svr}
       done