diff --git a/Dockerfile b/Dockerfile
index a6e50fa..e80384b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:22.04
+FROM ubuntu:22.04@sha256:962f6cadeae0ea6284001009daa4cc9a8c37e75d1f5191cf0eb83fe565b63dd7
 
 RUN apt-get update && \
     apt-get install -y coreutils wget zip libfontconfig1 && \