diff --git a/Dockerfile b/Dockerfile
index 3d69f06..bc03dba 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.23
+FROM alpine:3.23@sha256:5b10f432ef3da1b8d4c7eb6c487f2f5a8f096bc91145e68878dd4a5019afde11
 LABEL description="A complete, self-hosted Tiny Tiny RSS (TTRSS) environment." \
     maintainer="Julien Cabillot <dockerimages@cabillot.eu>"