diff --git a/php56.Dockerfile b/php56.Dockerfile
index 47547d6..6257ea1 100644
--- a/php56.Dockerfile
+++ b/php56.Dockerfile
@@ -1,10 +1,14 @@
 FROM php:5.6-cli
 
-COPY --from=composer:2.2.12 /usr/bin/composer /usr/bin/composer
+COPY --from=composer:2.2.23 /usr/bin/composer /usr/bin/composer
+
+RUN sed -i s/deb.debian.org/archive.debian.org/g /etc/apt/sources.list \
+    && sed -i s/security.debian.org/archive.debian.org/g /etc/apt/sources.list \
+    && sed -i /stretch-updates/d /etc/apt/sources.list
 
 RUN apt-get update && apt-get install -y \
       zip \
-    && rm -rf /var/cache/apt/
+    && rm -rf /var/cache/apt/lists/*
 
 RUN pecl install xdebug-2.5.5 \
     && docker-php-ext-enable xdebug