diff --git a/.docker/Dockerfile b/.docker/Dockerfile
index 5de0dcc0..5508c66d 100644
--- a/.docker/Dockerfile
+++ b/.docker/Dockerfile
@@ -1,4 +1,4 @@
-FROM composer
+FROM composer:1.8.0
 
 RUN apk add --update libxslt-dev && \
     docker-php-ext-install xsl