diff --git a/.docker/Dockerfile b/.docker/Dockerfile
index 4ae35a4..c15c370 100644
--- a/.docker/Dockerfile
+++ b/.docker/Dockerfile
@@ -1,4 +1,4 @@
-FROM php:7.1-fpm
+FROM php:8.5-fpm@sha256:f71f705efb76fe4860505945592c64a5d964e7edcb1b5875693d60f531f87200
 
 COPY . .
 WORKDIR .