diff --git a/README.md b/README.md
index 2a13268..1df9668 100644
--- a/README.md
+++ b/README.md
@@ -9,9 +9,8 @@ IRuby is a Ruby kernel for [Jupyter project](http://try.jupyter.org/).
 ## Installation
 How to set up [ZeroMQ](http://zeromq.org/) depends on your environment.
 You can use one of the following libraries. 
+* [ffi-rzmq](https://github.com/chuckremes/ffi-rzmq) and [libzmq](https://github.com/zeromq/libzmq) >= 3.2
 * [CZTop](https://gitlab.com/paddor/cztop) and [CZMQ](https://github.com/zeromq/czmq) >= 4.0.0
-* [ffi-rzmq](https://github.com/chuckremes/ffi-rzmq) and [libzmq
-](https://github.com/zeromq/libzmq) >= 3.2
 
 ### Ubuntu
 Install Jupyter with [Anaconda](https://www.anaconda.com/) (recommended). 
@@ -25,6 +24,10 @@ sudo apt install git libzmq-dev autoconf pkg-config
 git clone https://github.com/zeromq/czmq
 cd czmq
 ./autogen.sh && ./configure && sudo make && sudo make install
+
+gem install cztop
+gem install iruby --pre
+iruby register --force
 ```
 
 #### Setup ZeroMQ on Ubuntu 17.04 to 18.10
@@ -33,11 +36,8 @@ Use official packages.
 ```shell
 sudo apt install libtool libffi-dev ruby ruby-dev make
 sudo apt install libzmq3-dev libczmq-dev
-```
 
-#### Install CZTop and IRuby
-```shell
-gem install cztop
+gem install ffi-rzmq
 gem install iruby --pre
 iruby register --force
 ```