diff --git a/README.md b/README.md
index 6f978db..8ddf47a 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,10 @@ The module provides a migrate source plugin for importing data from spreadsheet
 
 [The supported source files](https://github.com/PHPOffice/PhpSpreadsheet#file-formats-supported) includes .ods, .xls, .xlsx, .csv.
 
+## Installing PHPSpreadsheet
+
+Usually we use [Composer](https://getcomposer.org/) to install dependencies in Drupal 8. Unfortunately, the `composer.json` file provided in the module root directory is not automatically parsed when the module gets enabled. For this reason, before installing the module, relevant lines from that file should be copied in the project top `composer.json` file. The entries under `"repositories"`, `"require"` and `"autoload"` > `"psr-4"` should be copied under the same arrays, in the top project's `composer.json`. Then a `$ composer update` should be issued.
+
 ## Usage
 
 In your migration file: