diff --git a/docker/README.md b/docker/README.md
index 09199684e13f47bc04b5fca2f7a5ace68f74d4bd..2cca2945163c81123f87dce956e6ef28c588d505 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -1,3 +1,15 @@
 # Docker container (base) for the converter software
 
 This directory contains all the files needed to create the base Docker image used for the converter software in [projects](projects/).
+
+<!--
+build:
+- go to repo root
+- execute: docker build -f docker/Dockerfile -t mmcifconverter:20220427
+
+run interactive shell for development:
+- make sure files exist: /Users/stefan/Projects/ma-converters.git/projects/pointmutations-haddock/.docker-bash-history
+- execute:
+docker run --rm -i -v /Users/stefan/.bash_profile:/home/mmcif/.bash_profile -v /Users/stefan/.bash_aliases:/home/mmcif/.bash_aliases -v /Users/stefan/.bashrc:/home/mmcif/.bashrc -v /Users/stefan/Projects/ma-converters.git/projects/pointmutations-haddock/.docker-bash-history:/home/mmcif/.bash_history -v /Users/stefan/Projects/ma-converters.git/:/develop -t mmcifconverter:20220427 bash
+
+ -->
diff --git a/pyproject.toml b/pyproject.toml
index b95b5ec25a2eef2ff5629d07e649ba9b7f960547..90392da16a7316df546dc4d16157320679e4943f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,11 @@
 [tool.black]
 line-length=80
 
+[tool.pylint.MASTER]
+# A comma-separated list of package or module names from where C extensions may
+# be loaded. Extensions are loading into the active Python interpreter and may
+# run arbitrary code
+extension-pkg-allow-list='ujson'
+
 [tool.pylint.REPORTS]
 reports='no'