diff --git a/doc/installation.md b/doc/installation.md
index 823bd483ad6..f9da6ddb2f1 100644
--- a/doc/installation.md
+++ b/doc/installation.md
@@ -55,7 +55,7 @@ The installation consists of 6 steps:
     sudo apt-get update
     sudo apt-get upgrade
 
-    sudo apt-get install -y git-core wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server git-core python-dev python-pip sendmail
+    sudo apt-get install -y git-core wget curl gcc checkinstall libxml2-dev libxslt-dev sqlite3 libsqlite3-dev libcurl4-openssl-dev libreadline-dev libc6-dev libssl-dev libmysql++-dev make build-essential zlib1g-dev libicu-dev redis-server openssh-server git-core python-dev python-pip libyaml-dev sendmail
 
 # 2. Install ruby