diff --git a/composer/Dockerfile b/composer/Dockerfile
index a9b2b4c..2ef0d43 100644
--- a/composer/Dockerfile
+++ b/composer/Dockerfile
@@ -2,5 +2,4 @@ FROM composer
 
 MAINTAINER yesterday679 <yesterday679@gmail.com>
 
-RUN docker-php-ext-install bcmath \
-    && composer config -g repo.packagist composer https://packagist.phpcomposer.com
+RUN composer config -g repo.packagist composer https://packagist.phpcomposer.com