diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@
     * Node.js version 5.0.0 or newer is required.
     * Install dependencies with `npm install`
     * Install babel presets: `npm install babel-preset-es2015 babel-preset-es2016`
-* Initialize database: `mix amnesia.create -db KolabChat.Database --disk`
+* Initialize database: `mix amnesia.create -d KolabChat.Database --disk`
 * Start Phoenix endpoint with `mix phoenix.server`
 
 Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.