diff --git a/doc/api/hooks_server-side.md b/doc/api/hooks_server-side.md
index 32a09ecf4..c46da350c 100644
--- a/doc/api/hooks_server-side.md
+++ b/doc/api/hooks_server-side.md
@@ -617,14 +617,14 @@ is sent to the client. Plugins can use this hook to manipulate the
 configuration. (Example: Add a tracking ID for an external analytics tool that
 is used client-side.)
 
-The clientVars function must return a Promise that resolves to an object (or
-null/undefined) whose properties will be merged into `context.clientVars`.
-Returning `callback(value)` will return a Promise that is resolved to `value`.
-
-You can modify `context.clientVars` to change the values sent to the client, but
-beware: async functions from other clientVars plugins might also be reading or
-manipulating the same `context.clientVars` object. For this reason it is
-recommended you return an object rather than modify `context.clientVars`.
+You can manipulate `clientVars` in two different ways:
+* Return an object. The object will be merged into `clientVars` via
+  `Object.assign()`, so any keys that already exist in `clientVars` will be
+  overwritten by the values in the returned object.
+* Modify `context.clientVars`. Beware: Other plugins might also be reading or
+  manipulating the same `context.clientVars` object. To avoid race conditions,
+  you are encouraged to return an object rather than modify
+  `context.clientVars`.
 
 If needed, you can access the user's account information (if authenticated) via
 `context.socket.client.request.session.user`.
@@ -645,8 +645,6 @@ exports.clientVars = (hookName, context, callback) => {
 };
 ```
 
-This can be accessed on the client-side using `clientVars.currentYear`.
-
 ## getLineHTMLForExport
 Called from: src/node/utils/ExportHtml.js