diff --git a/packages/cra-template-pwa-typescript/template/src/serviceWorkerRegistration.ts b/packages/cra-template-pwa-typescript/template/src/serviceWorkerRegistration.ts
index efbf2ac..77a8cf7 100644
--- a/packages/cra-template-pwa-typescript/template/src/serviceWorkerRegistration.ts
+++ b/packages/cra-template-pwa-typescript/template/src/serviceWorkerRegistration.ts
@@ -95,6 +95,26 @@ function registerValidSW(swUrl: string, config?: Config) {
           }
         };
       };
+
+      // in the case a page is loaded an a service worker is already waiting
+      // we should trigger the onUpdate callback
+      const waitingWorker = registration.waiting;
+      if (waitingWorker) {
+        if (navigator.serviceWorker.controller && waitingWorker.state === 'installed') {
+          // At this point, the updated precached content has been fetched,
+          // but the previous service worker will still serve the older
+          // content until all client tabs are closed.
+          console.log(
+            'New content is available and will be used when all ' +
+              'tabs for this page are closed. See https://cra.link/PWA.'
+          );
+
+          // Execute callback
+          if (config && config.onUpdate) {
+            config.onUpdate(registration);
+          }
+        }
+      }
     })
     .catch((error) => {
       console.error('Error during service worker registration:', error);
diff --git a/packages/cra-template-pwa/template/src/serviceWorkerRegistration.js b/packages/cra-template-pwa/template/src/serviceWorkerRegistration.js
index 2262ecd..94f6746 100644
--- a/packages/cra-template-pwa/template/src/serviceWorkerRegistration.js
+++ b/packages/cra-template-pwa/template/src/serviceWorkerRegistration.js
@@ -90,6 +90,26 @@ function registerValidSW(swUrl, config) {
           }
         };
       };
+
+      // in the case a page is loaded an a service worker is already waiting
+      // we should trigger the onUpdate callback
+      const waitingWorker = registration.waiting;
+      if (waitingWorker) {
+        if (navigator.serviceWorker.controller && waitingWorker.state === 'installed') {
+          // At this point, the updated precached content has been fetched,
+          // but the previous service worker will still serve the older
+          // content until all client tabs are closed.
+          console.log(
+            'New content is available and will be used when all ' +
+              'tabs for this page are closed. See https://cra.link/PWA.'
+          );
+
+          // Execute callback
+          if (config && config.onUpdate) {
+            config.onUpdate(registration);
+          }
+        }
+      }
     })
     .catch((error) => {
       console.error('Error during service worker registration:', error);