diff --git a/README.md b/README.md
index f8aadd0c..e303ca14 100644
--- a/README.md
+++ b/README.md
@@ -43,8 +43,10 @@ If you want to use the app with your own server and want web push notification t
 
 * Register at https://firebase.google.com/, set up the project if you have not done so already.
 * Follow instructions to create a web application https://support.google.com/firebase/answer/9326094 in your project.
-* Follow instructions at https://support.google.com/firebase/answer/7015592 to get a Firebase configuration object.
-* Locate `firebase-init.js` in the root folder of your copy of TinodeWeb app. Copy-paste configuration object to `firebase-init.js`. Copy `Web Push certificate` (Project Settings -> Cloud Messaging -> Web configuration -> Web Push certificates) to `messagingVapidKey` field.
+* Follow instructions at https://support.google.com/firebase/answer/7015592 to get a Firebase configuration object ("Firebase SDK snippet").
+* Locate `firebase-init.js` in the root folder of your copy of TinodeWeb app. Copy-paste the following keys from the configuration object to `firebase-init.js`: `apiKey`, `messagingSenderId`, `projectId`, `appId` (you may copy all keys).
+* Copy `Web Push certificate` (Project Settings -> Cloud Messaging -> Web configuration -> Web Push certificates) to `messagingVapidKey` field in `firebase-init.js`.
+* Double check that `firebase-init.js` contains the following keys: `apiKey`, `messagingSenderId`, `projectId`, `appId`, `messagingVapidKey`. The file may contain other optional keys.
 * Copy Google-provided server key to `tinode.conf`, see details [here](https://github.com/tinode/chat/blob/master/docs/faq.md#q-how-to-setup-fcm-push-notifications).
 
 ## Responsive design
diff --git a/firebase-init.js b/firebase-init.js
index 169b0110..e683f3cd 100644
--- a/firebase-init.js
+++ b/firebase-init.js
@@ -1,12 +1,13 @@
 // Get these values for your project from the https://console.firebase.google.com/
 const FIREBASE_INIT = {
   // Set up a web application in console then get the config object.
+  // The following keys are copied from the object:
   apiKey: "AIzaSyD6X4ULR-RUsobvs1zZ2bHdJuPz39q2tbQ",
   messagingSenderId: "114126160546",
   projectId: "tinode-1000",
   appId: "1:114126160546:web:aca6ea2981feb81fb44dfb",
   // Project Settings -> Cloud Messaging -> Web configuration -> Web Push certificates.
-  // This value IS NOT included in the generated js config you can download from
+  // This value IS NOT included in the generated js config you get from
   // the firebase console. It needs to be added separately.
   messagingVapidKey: "BOgQVPOMzIMXUpsYGpbVkZoEBc0ifKY_f2kSU5DNDGYI6i6CoKqqxDd7w7PJ3FaGRBgVGJffldETumOx831jl58"
 };