diff --git a/apps/acf-extension/src/background/index.ts b/apps/acf-extension/src/background/index.ts
index 0ead64e9..5ff45fe8 100644
--- a/apps/acf-extension/src/background/index.ts
+++ b/apps/acf-extension/src/background/index.ts
@@ -77,6 +77,13 @@ try {
   };
   Runtime.onMessageExternal(onMessageListener);
   Runtime.onMessage(onMessageListener);
+
+  auth.authStateReady().then(() => {
+    const clientId = auth.currentUser?.uid;
+    if (clientId) {
+      chrome.storage.local.set({ clientId });
+    }
+  });
 } catch (error) {
   if (error instanceof Error) {
     googleAnalytics?.fireErrorEvent({ name: error.name, error: error.message, additionalParams: { page: 'background' } });
diff --git a/libs/shared/google-analytics/src/lib/google-analytics-background.ts b/libs/shared/google-analytics/src/lib/google-analytics-background.ts
index df427462..28599393 100644
--- a/libs/shared/google-analytics/src/lib/google-analytics-background.ts
+++ b/libs/shared/google-analytics/src/lib/google-analytics-background.ts
@@ -5,8 +5,8 @@ import { FireErrorEventParams, FireEventParams, FirePageViewEventParams } from '
 export class GoogleAnalyticsBackground {
   debug: boolean;
   constructor(
-    private MEASUREMENT_ID?: string,
-    private API_SECRET?: string,
+    private readonly MEASUREMENT_ID?: string,
+    private readonly API_SECRET?: string,
     debug = false
   ) {
     this.MEASUREMENT_ID = MEASUREMENT_ID;