diff --git a/docs/content/doc/advanced/external-renderers.en-us.md b/docs/content/doc/advanced/external-renderers.en-us.md
index 94c8763a78..dbba5e9f29 100644
--- a/docs/content/doc/advanced/external-renderers.en-us.md
+++ b/docs/content/doc/advanced/external-renderers.en-us.md
@@ -36,12 +36,12 @@ FROM gitea/gitea:{{< version >}}
 COPY custom/app.ini /data/gitea/conf/app.ini
 [...]
 
-RUN apk --no-cache add asciidoctor freetype freetype-dev gcc g++ libpng python-dev py-pip python3-dev py3-pip py3-pyzmq
+RUN apk --no-cache add asciidoctor freetype freetype-dev gcc g++ libpng libffi-dev python-dev py-pip python3-dev py3-pip py3-pyzmq
 # install any other package you need for your external renderers
 
 RUN pip3 install --upgrade pip
 RUN pip3 install -U setuptools
-RUN pip3 install jupyter matplotlib docutils 
+RUN pip3 install jupyter docutils 
 # add above any other python package you may need to install
 ```