diff --git a/Development.md b/Development.md
index ad0dbf1..f1bd6d6 100644
--- a/Development.md
+++ b/Development.md
@@ -8,6 +8,7 @@ The `master` branch contains source code for the latest stable release. In will
 
 1. Fork this repository to your own account
 2. Create a new branch from **the `dev` branch**. If you are developing a new feature, please name your branch `feature/your-new-feature`. If you are working on a bug fix, please name it `fix/your-bug-fix`
+3. Run `make setup` to set up the development environment. Now you are ready to develop Mango!
 3. Please write unit tests for your Crytal code if possible. The test files are in the `spec/` directory
 4. Please run `make test` (unit testing) and `make check` (linter and static analyzer) before submitting your PR
 5. When you are done, submit a PR to merge it to **the `dev` branch** in the main repository. Your code will be reviewed and we may ask you to make further changes