diff --git a/Dockerfile b/Dockerfile
index 6e61ccf..187279f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,6 +13,6 @@ RUN set -ex \
     && pecl install -o xdebug-2.9.8 && docker-php-ext-enable xdebug \
     && apk del build-dependencies
 
-ARG COMPOSER_VERSION=1.10.15
+ARG COMPOSER_VERSION=2.0.3
 RUN curl -sS https://getcomposer.org/installer | php -- \
     --install-dir=/usr/local/bin --filename=composer --version=$COMPOSER_VERSION