diff --git a/php7.4/dockerfile b/php7.4/dockerfile
index e1cdb57..8fec16b 100644
--- a/php7.4/dockerfile
+++ b/php7.4/dockerfile
@@ -36,9 +36,9 @@ RUN apk add --no-cache --virtual .build-deps \
     && curl -s https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin/ --filename=composer \
     && apk del -f .build-deps
 
-RUN apk add shadow && usermod -u 1000 www-data && groupmod -g 1000 www-data
+RUN apk --no-cache add shadow && \
+    usermod -u 1000 www-data && \
+    groupmod -g 1000 www-data
 
 # 修改 composer 为国内镜像
 RUN composer config -g repo.packagist composer https://mirrors.cloud.tencent.com/composer/
-
-USER www-data
\ No newline at end of file