diff --git a/Dockerfile b/Dockerfile
index ba1201b..20b1f61 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM composer:2.2.2 as builder
+FROM composer:2.3.9 as builder
 
 COPY . /opt/phpdoc
 WORKDIR /opt/phpdoc