diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98c1909..68c48eb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,14 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+## [5.2.1](https://github.com/cotes2020/jekyll-theme-chirpy/compare/v5.2.0...v5.2.1) (2022-06-17)
+
+
+### Bug Fixes
+
+* exclude CHANGELOG from output ([971fe03](https://github.com/cotes2020/jekyll-theme-chirpy/commit/971fe03ec329ae49e7d60fe3af6101cfbd1acd6c))
+* **PWA:** sometimes update notification is not triggered ([96af729](https://github.com/cotes2020/jekyll-theme-chirpy/commit/96af7291ea5b2c5ed6372e7b6f7725e67c69f1ba))
+
 ## [5.2.0](https://github.com/cotes2020/jekyll-theme-chirpy/compare/v5.1.0...v5.2.0) (2022-06-09)
 
 
diff --git a/_config.yml b/_config.yml
index ad085a8..640180d 100644
--- a/_config.yml
+++ b/_config.yml
@@ -185,6 +185,7 @@ exclude:
   - '*.gemspec'
   - tools
   - README.md
+  - CHANGELOG.md
   - LICENSE
   - gulpfile.js
   - node_modules
diff --git a/_javascript/copyright b/_javascript/copyright
index fb4de71..2241015 100644
--- a/_javascript/copyright
+++ b/_javascript/copyright
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/_sass/jekyll-theme-chirpy.scss b/_sass/jekyll-theme-chirpy.scss
index 29b6e44..85cbf28 100644
--- a/_sass/jekyll-theme-chirpy.scss
+++ b/_sass/jekyll-theme-chirpy.scss
@@ -1,7 +1,7 @@
 /*!
  * The styles for Jekyll theme Chirpy
  *
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/dist/categories.min.js b/assets/js/dist/categories.min.js
index 8bed3a9..34f42f5 100644
--- a/assets/js/dist/categories.min.js
+++ b/assets/js/dist/categories.min.js
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/dist/commons.min.js b/assets/js/dist/commons.min.js
index bd78fa3..249d2c7 100644
--- a/assets/js/dist/commons.min.js
+++ b/assets/js/dist/commons.min.js
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/dist/home.min.js b/assets/js/dist/home.min.js
index cb2516c..0fa7b91 100644
--- a/assets/js/dist/home.min.js
+++ b/assets/js/dist/home.min.js
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/dist/misc.min.js b/assets/js/dist/misc.min.js
index cb2516c..0fa7b91 100644
--- a/assets/js/dist/misc.min.js
+++ b/assets/js/dist/misc.min.js
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/dist/page.min.js b/assets/js/dist/page.min.js
index 2e817ac..54a9e55 100644
--- a/assets/js/dist/page.min.js
+++ b/assets/js/dist/page.min.js
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/dist/post.min.js b/assets/js/dist/post.min.js
index edd7514..332b0fc 100644
--- a/assets/js/dist/post.min.js
+++ b/assets/js/dist/post.min.js
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/dist/pvreport.min.js b/assets/js/dist/pvreport.min.js
index 157ef40..2506259 100644
--- a/assets/js/dist/pvreport.min.js
+++ b/assets/js/dist/pvreport.min.js
@@ -1,5 +1,5 @@
 /*!
- * Chirpy v5.2.0 (https://github.com/cotes2020/jekyll-theme-chirpy/)
+ * Chirpy v5.2.1 (https://github.com/cotes2020/jekyll-theme-chirpy/)
  * © 2019 Cotes Chung
  * MIT Licensed
  */
diff --git a/assets/js/pwa/app.js b/assets/js/pwa/app.js
index 9eb1a03..ab4b174 100644
--- a/assets/js/pwa/app.js
+++ b/assets/js/pwa/app.js
@@ -3,50 +3,37 @@ layout: compress
 permalink: '/app.js'
 ---
 
-const keyWaiting = 'sw-waiting';
 const $notification = $('#notification');
 const $btnRefresh = $('#notification .toast-body>button');
 
-function skipWating(registration) {
-  registration.waiting.postMessage('SKIP_WAITING');
-  localStorage.removeItem(keyWaiting);
-}
-
 if ('serviceWorker' in navigator) {
   /* Registering Service Worker */
   navigator.serviceWorker.register('{{ "/sw.js" | relative_url }}')
     .then(registration => {
-      if (registration) {
-        registration.addEventListener('updatefound', () => {
-          let serviceWorker = registration.installing;
 
-          serviceWorker.addEventListener('statechange', () => {
-            if (serviceWorker.state === 'installed') {
-              if (navigator.serviceWorker.controller) {
-                $notification.toast('show');
-                /* in case the user ignores the notification */
-                localStorage.setItem(keyWaiting, true);
-              }
-            }
-          });
-        });
-
-        $btnRefresh.click(() => {
-          skipWating(registration);
-          $notification.toast('hide');
-        });
-
-        if (localStorage.getItem(keyWaiting)) {
-          if (registration.waiting) {
-            /* there's a new Service Worker waiting to be activated */
-            $notification.toast('show');
-          } else {
-            /* closed all open pages after receiving notification */
-            localStorage.removeItem(keyWaiting);
-          }
-        }
+      /* in case the user ignores the notification */
+      if (registration.waiting) {
+        $notification.toast('show');
       }
-    });
+
+      registration.addEventListener('updatefound', () => {
+        registration.installing.addEventListener('statechange', () => {
+          if (registration.waiting) {
+            if (navigator.serviceWorker.controller) {
+              $notification.toast('show');
+            }
+          }
+        });
+      });
+
+      $btnRefresh.click(() => {
+        if (registration.waiting) {
+          registration.waiting.postMessage('SKIP_WAITING');
+        }
+        $notification.toast('hide');
+      });
+    }
+  );
 
   let refreshing = false;
 
diff --git a/jekyll-theme-chirpy.gemspec b/jekyll-theme-chirpy.gemspec
index 8d972e3..5cfade7 100644
--- a/jekyll-theme-chirpy.gemspec
+++ b/jekyll-theme-chirpy.gemspec
@@ -2,7 +2,7 @@
 
 Gem::Specification.new do |spec|
   spec.name          = "jekyll-theme-chirpy"
-  spec.version       = "5.2.0"
+  spec.version       = "5.2.1"
   spec.authors       = ["Cotes Chung"]
   spec.email         = ["cotes.chung@gmail.com"]
 
diff --git a/package.json b/package.json
index 5a47ed9..ffcb38f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "jekyll-theme-chirpy",
-  "version": "5.2.0",
+  "version": "5.2.1",
   "description": "A minimal, responsive, and powerful Jekyll theme for presenting professional writing.",
   "repository": {
     "type": "git",