diff --git a/Dockerfile b/Dockerfile
index b6e0be2..7e02f27 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,13 +1,15 @@
-# elecena.pl (c) 2015-2021
+# elecena.pl (c) 2015-2022
 
 # https://hub.docker.com/_/php
-ARG PHP_VERSION=8.1.0
+ARG PHP_VERSION=8.1.2
 
 # https://hub.docker.com/_/python/
-ARG PYTHON_VERSION=3.10.1
+ARG PYTHON_VERSION=3.10.2
 
 # https://hub.docker.com/_/composer
-FROM composer:2 AS php-composer
+ARG COMPOSER_VERSION=2.2.6
+
+FROM composer:$COMPOSER_VERSION AS php-composer
 RUN /usr/bin/composer -v
 
 #
@@ -20,6 +22,12 @@ RUN apk add \
 		libxml2-dev \
 		libxslt-dev
 
+# fixes "sockets" compilation issues
+# sendrecvmsg.c:128:19: error: invalid application of 'sizeof' to incomplete type 'struct cmsgcred'
+#
+# see https://github.com/docker-library/php/issues/1245#issuecomment-1019957169
+ENV CFLAGS="$CFLAGS -D_GNU_SOURCE"
+
 RUN docker-php-ext-install \
 	bz2 \
 	calendar \
@@ -41,6 +49,7 @@ RUN which php; php -v; php -m; php -i | grep ini
 #
 FROM python:$PYTHON_VERSION-alpine
 ARG PHP_VERSION
+ARG COMPOSER_VERSION
 
 RUN pip install virtualenv && rm -rf /root/.cache
 RUN python -V
@@ -64,6 +73,7 @@ RUN php -r '$res = iconv("utf-8", "utf-8//IGNORE", "fooą");'
 
 RUN php -v; php -m; php -i | grep ini
 ENV PHP_VERSION $PHP_VERSION
+ENV COMPOSER_VERSION $COMPOSER_VERSION
 
 # add an info script
 WORKDIR /opt
diff --git a/README.md b/README.md
index 9500b91..0be4649 100644
--- a/README.md
+++ b/README.md
@@ -21,15 +21,15 @@ elecena/python-php   latest      4eb6703d62df   2 seconds ago   105MB
 $ docker run -it elecena/python-php sh info.sh
 
 ### Python
-Python 3.10.1
-virtualenv 20.10.0 from /usr/local/lib/python3.10/site-packages/virtualenv/__init__.py
+Python 3.10.2
+virtualenv 20.13.1 from /usr/local/lib/python3.10/site-packages/virtualenv/__init__.py
 
 ### PHP
-PHP 8.1.0 (cli) (built: Nov 30 2021 07:15:23) (NTS)
+PHP 8.1.2 (cli) (built: Jan 21 2022 21:38:22) (NTS)
 Copyright (c) The PHP Group
-Zend Engine v4.1.0, Copyright (c) Zend Technologies
-    with Zend OPcache v8.1.0, Copyright (c), by Zend Technologies
-Composer version 2.1.14 2021-11-30 10:51:43
+Zend Engine v4.1.2, Copyright (c) Zend Technologies
+    with Zend OPcache v8.1.2, Copyright (c), by Zend Technologies
+Composer version 2.2.6 2022-02-04 17:00:38
 [PHP Modules]
 bz2
 calendar