diff --git a/Dockerfile b/Dockerfile
index 427873a..4a03d09 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,12 +2,13 @@ FROM php:cli
 
 WORKDIR /app
 
-RUN apt-get update \
-  && apt-get install -y --no-install-recommends \
-  libonig-dev xclip xsel wl-clipboard
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends libonig-dev xclip xsel wl-clipboard && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
 
 RUN docker-php-ext-install mbstring
 
 COPY ./h-m-m .
 
-CMD ./h-m-m $file
+ENTRYPOINT ["./h-m-m"]
diff --git a/readme.md b/readme.md
index ff832c0..a45251e 100644
--- a/readme.md
+++ b/readme.md
@@ -322,8 +322,11 @@ It's also possible to execute `h-m-m` through docker (or podman):
 # Build the image
 docker build -t hmm .
 
-# Run it
-docker run --rm -it -v $(pwd):/app/ hmm
+# Run it (mount $pwd for file access, X11 & DISLAY for clipboard access)
+docker run --rm -it -v $(pwd):/app/ -v /tmp/.X11-unix:/tmp/.X11-unix -e DISPLAY=$DISPLAY hmm
+
+# Convinience
+alias hmm='docker run --rm -it -v $(pwd):/app/ -v /tmp/.X11-unix:/tmp/.X11-unix -e DISPLAY=$DISPLAY hmm'
 ```