diff --git a/Dockerfile b/Dockerfile
index 9996409..b8792dc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM php:7.4-apache
+FROM php:7.4-apache@sha256:c9d7e608f73832673479770d66aacc8100011ec751d1905ff63fae3fe2e0ca6d
 LABEL maintainer="Julien Cabillot <dockerimages@cabillot.eu>"