diff --git a/vars/functions.groovy b/vars/functions.groovy
index ac9ba79..e7a195b 100644
--- a/vars/functions.groovy
+++ b/vars/functions.groovy
@@ -140,7 +140,7 @@
     def jnlpContainer = containerTemplate(name: 'jnlp',
                                           image: 'jenkins/jnlp-slave:alpine')
     def debianContainer = containerTemplate(name: 'debian',
-                                            image: 'gcr.io/mendel-linux-cloud-infra/mendel-builder:latest',
+                                            image: 'gcr.io/mendel-linux-cloud-infra/mendel-builder@sha256:30f5a2b1b85e678fc25d4322226a55e571ee7a4c344a35d1b13c3e496d4bbe3f',
                                             command: 'cat',
                                             args: '',
                                             ttyEnabled: true,