diff --git a/docs/sources/examples/mongodb.rst b/docs/sources/examples/mongodb.rst
index e351b9b384..c8b46c2544 100644
--- a/docs/sources/examples/mongodb.rst
+++ b/docs/sources/examples/mongodb.rst
@@ -24,7 +24,7 @@ Create an empty file called ``Dockerfile``:
touch Dockerfile
Next, define the parent image you want to use to build your own image on top of.
-Here, we’ll use `CentOS `_ (tag: ``latest``)
+Here, we’ll use `Ubuntu `_ (tag: ``latest``)
available on the `docker index`_:
.. code-block:: bash
@@ -65,11 +65,14 @@ run without needing to provide a special configuration file)
# Create the MongoDB data directory
RUN mkdir -p /data/db
-Finally, we'll expose the standard port that MongoDB runs on (27107)
+Finally, we'll expose the standard port that MongoDB runs on (27107) as well as
+add an entrypoint that runs the standard --help command by default.
.. code-block:: bash
EXPOSE 27017
+ ENTRYPOINT [ "/usr/bin/mongod" ]
+ CMD [ "--help" ]
Now, lets build the image which will go through the ``Dockerfile`` we made and
run all of the commands.