diff --git a/source/installation/installation.rst b/source/installation/installation.rst
index 1cfc4b43f..8aafc2131 100644
--- a/source/installation/installation.rst
+++ b/source/installation/installation.rst
@@ -25,7 +25,7 @@ Requirements
 Server requirements
 ^^^^^^^^^^^^^^^^^^^^
 
-* a postgresql database. The minimum version is postgresql 9.3, but we are working on developing on the 9.4 branch, which will provide features which will ease developper work
+* a postgresql database, with the `*unaccent* extension`_ enabled. The minimum version is postgresql 9.3, but we are working on developing on the 9.4 branch, which will provide features which will ease developper work
 * php 5.5
 * If you run Chill in production mode, you should also install a web server (apache, ngnix, ...). We may use php built-in server for testing and development.
 
@@ -33,6 +33,10 @@ Within this documentation, we are going to describe installation on Unix systems
 
 You won't need any web server for demonstration or development.
 
+.. note::
+
+   Installing unaccent extension on ther server is possible with the package `postgresql-contrib-9.x` (replace 9.x with your server version). The extension may be enabled with running `CREATE EXTENSION unaccent;` in the database, with a superuser account.
+
 Client requirements
 ^^^^^^^^^^^^^^^^^^^
 
@@ -188,3 +192,4 @@ Your server should now be available at `http://localhost:8000`. Type this addres
 .. _composer: https://getcomposer.org
 .. _Firefox: https://www.mozilla.org
 .. _symfony framework: http://symfony.com
+.. _*unaccent* extension: http://www.postgresql.org/docs/current/static/unaccent.html