diff --git a/web/docs/dev.md b/web/docs/dev.md
index 7f0247357a77ae21b74f27c4b1d7b17a53991693..0b980c1e2836430d77d070f32db6dc9b6f837473 100644
--- a/web/docs/dev.md
+++ b/web/docs/dev.md
@@ -6,12 +6,19 @@ We recommend VS Code, with the following extensions:
 
 - Prettier - reformats your code automatically (enable format on save),
 - ESLint - warns you about issues
-- vscode-styled-components - improved support for our CSS in JS library
 
-Make sure you're on yarn 1.x series (aka yarn "classic").
+Optionally, if you're going to make many changes to the CSS in JS, you might
+also find it useful to install the _vscode-styled-components_ extension.
 
 ## Yarn commands
 
+Make sure you're on yarn 1.x series (aka yarn "classic").
+
+### yarn install
+
+Installs dependencies. This needs to be done once, and thereafter wherever there
+is a change in `yarn.lock` (e.g. when pulling the latest upstream).
+
 ### yarn dev:*
 
 Launch the app in development mode. There is one `yarn dev:foo` for each app,