diff --git a/README.md b/README.md
index 3466a70..9742f99 100644
--- a/README.md
+++ b/README.md
@@ -106,7 +106,8 @@ gamja default settings can be set using a `config.json` file at the root:
 		// require it, "disabled" to never ask for a password, or "external" to
 		// use SASL EXTERNAL. Defaults to "optional".
 		"auth": "optional",
-		// Default nickname (string).
+		// Default nickname (string). If it contains a "*" character, it will
+		// be replaced with a random string.
 		"nick": "asdf",
 		// Don't display the login UI, immediately connect to the server
 		// (boolean).
diff --git a/components/app.js b/components/app.js
index 7d9ece0..dfc4cf7 100644
--- a/components/app.js
+++ b/components/app.js
@@ -323,6 +323,14 @@ export default class App extends Component {
 
 		this.config = config;
 
+		if (!connectParams.nick && connectParams.autoconnect) {
+			connectParams.nick = "user-*";
+		}
+		if (connectParams.nick && connectParams.nick.includes("*")) {
+			let placeholder = Math.random().toString(36).substr(2, 7);
+			connectParams.nick = connectParams.nick.replace("*", placeholder);
+		}
+
 		if (autojoin.length > 0) {
 			if (connectParams.autoconnect) {
 				// Ask the user whether they want to join that new channel.