diff --git a/container-action/Dockerfile b/container-action/Dockerfile
index 862b0230..36839182 100644
--- a/container-action/Dockerfile
+++ b/container-action/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:24.04 AS builder
+FROM ubuntu:24.04@sha256:dfbcc2701b935fa13b53ee525549d83c27c3560055c578768f1f4d4f1b8bde32 AS builder
 
 LABEL Description="Custom RSK node image to execute Rootstock Integration Tests"