diff --git a/Dockerfile b/Dockerfile
index bb031dd..5dd5cae 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,6 +10,7 @@ RUN apt update && apt install -y \
     apt install /pandoc-2.9.2.1-1-amd64.deb && rm pandoc-2.9.2.1-1-amd64.deb && \
     wget https://github.com/lierdakil/pandoc-crossref/releases/download/v0.3.6.3/pandoc-crossref-Linux-2.9.2.1.tar.xz && \
     unxz pandoc-crossref-Linux-2.9.2.1.tar.xz && tar xvf pandoc-crossref-Linux-2.9.2.1.tar && mv pandoc-crossref /usr/bin/pandoc-crossref && \
+    chmod +x /usr/bin/pandoc-crossref && \
     rm pandoc-crossref-Linux-2.9.2.1.tar pandoc-crossref.1 && rm -rf /var/cache/apt/archives 
 ARG UID=1000
 ARG GID=1000
diff --git a/README b/README
deleted file mode 100644
index 25aca76..0000000
--- a/README
+++ /dev/null
@@ -1 +0,0 @@
-A Docker with Pandoc, with extra everything, including pandoc-crossref.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..6d2bce9
--- /dev/null
+++ b/README.md
@@ -0,0 +1,10 @@
+A Docker with Pandoc, with extra everything, including `pandoc-crossref`.
+
+Mount the directory with the source you want to build, for example the current
+working directory:
+
+```
+docker run -it --rm -v ./:/data my-pandoc:latest
+```
+
+The run your Pandoc build commands from within the container.