diff --git a/src/ia-bookreader/downloads/downloads.js b/src/ia-bookreader/downloads/downloads.js
index 9c13a5b2c..9a76e86f1 100644
--- a/src/ia-bookreader/downloads/downloads.js
+++ b/src/ia-bookreader/downloads/downloads.js
@@ -147,4 +147,6 @@ export class IABookDownloads extends LitElement {
     return [buttonStyles, mainCss];
   }
 }
-customElements.define('ia-book-downloads', IABookDownloads);
+if (!customElements.get('ia-book-downloads')) {
+  customElements.define('ia-book-downloads', IABookDownloads);
+}
diff --git a/src/ia-bookreader/ia-bookreader.js b/src/ia-bookreader/ia-bookreader.js
index 728645ea5..b1ba4fb89 100644
--- a/src/ia-bookreader/ia-bookreader.js
+++ b/src/ia-bookreader/ia-bookreader.js
@@ -663,4 +663,6 @@ export class IaBookReader extends LitElement {
   }
 }
 
-window.customElements.define("ia-bookreader", IaBookReader);
+if (!customElements.get('ia-bookreader')) {
+  window.customElements.define("ia-bookreader", IaBookReader);
+}
diff --git a/src/ia-bookreader/visual-adjustments/visual-adjustments.js b/src/ia-bookreader/visual-adjustments/visual-adjustments.js
index 8d33662f8..2b8e6d251 100644
--- a/src/ia-bookreader/visual-adjustments/visual-adjustments.js
+++ b/src/ia-bookreader/visual-adjustments/visual-adjustments.js
@@ -285,4 +285,6 @@ export class IABookVisualAdjustments extends LitElement {
     return [sharedStyles, main];
   }
 }
-customElements.define('ia-book-visual-adjustments', IABookVisualAdjustments);
+if (!customElements.get('ia-book-visual-adjustments')) {
+  customElements.define('ia-book-visual-adjustments', IABookVisualAdjustments);
+}
diff --git a/src/plugins/bookmarks/bookmark-button.js b/src/plugins/bookmarks/bookmark-button.js
index 8d75d44a4..5b7eb5569 100644
--- a/src/plugins/bookmarks/bookmark-button.js
+++ b/src/plugins/bookmarks/bookmark-button.js
@@ -62,4 +62,6 @@ export default class BookmarkButton extends LitElement {
   }
 }
 
-customElements.define('bookmark-button', BookmarkButton);
+if (!customElements.get('bookmark-button')) {
+  customElements.define('bookmark-button', BookmarkButton);
+}
diff --git a/src/plugins/bookmarks/bookmark-edit.js b/src/plugins/bookmarks/bookmark-edit.js
index 351b87136..5bc27251b 100644
--- a/src/plugins/bookmarks/bookmark-edit.js
+++ b/src/plugins/bookmarks/bookmark-edit.js
@@ -224,4 +224,6 @@ export class IABookmarkEdit extends LitElement {
     return [buttonCSS, bookmarkColorsCSS, bookmarkEditCSS];
   }
 }
-customElements.define('ia-bookmark-edit', IABookmarkEdit);
+if (!customElements.get('ia-bookmark-edit')) {
+  customElements.define('ia-bookmark-edit', IABookmarkEdit);
+}
diff --git a/src/plugins/bookmarks/bookmarks-list.js b/src/plugins/bookmarks/bookmarks-list.js
index 48adacf5c..6def2a71e 100644
--- a/src/plugins/bookmarks/bookmarks-list.js
+++ b/src/plugins/bookmarks/bookmarks-list.js
@@ -281,4 +281,6 @@ export class IABookmarksList extends LitElement {
     return [main, bookmarkColorsCSS];
   }
 }
-customElements.define('ia-bookmarks-list', IABookmarksList);
+if (!customElements.get('ia-bookmarks-list')) {
+  customElements.define('ia-bookmarks-list', IABookmarksList);
+}
diff --git a/src/plugins/bookmarks/bookmarks-loginCTA.js b/src/plugins/bookmarks/bookmarks-loginCTA.js
index 8b184a1ba..bc9d30c81 100644
--- a/src/plugins/bookmarks/bookmarks-loginCTA.js
+++ b/src/plugins/bookmarks/bookmarks-loginCTA.js
@@ -25,4 +25,6 @@ class BookmarksLogin extends LitElement {
   }
 }
 
-customElements.define('bookmarks-login', BookmarksLogin);
+if (!customElements.get('bookmarks-login')) {
+  customElements.define('bookmarks-login', BookmarksLogin);
+}
diff --git a/src/plugins/bookmarks/delete-modal-actions.js b/src/plugins/bookmarks/delete-modal-actions.js
index ecb20d905..6c802882b 100644
--- a/src/plugins/bookmarks/delete-modal-actions.js
+++ b/src/plugins/bookmarks/delete-modal-actions.js
@@ -46,4 +46,6 @@ export default class DeleteModalActions extends LitElement {
   }
 }
 
-customElements.define('delete-modal-actions', DeleteModalActions);
+if (!customElements.get('delete-modal-actions')) {
+  customElements.define('delete-modal-actions', DeleteModalActions);
+}
diff --git a/src/plugins/bookmarks/ia-bookmarks.js b/src/plugins/bookmarks/ia-bookmarks.js
index b0c05186f..3d3635601 100644
--- a/src/plugins/bookmarks/ia-bookmarks.js
+++ b/src/plugins/bookmarks/ia-bookmarks.js
@@ -546,4 +546,6 @@ class IABookmarks extends LitElement {
   }
 }
 
-customElements.define('ia-bookmarks', IABookmarks);
+if (!customElements.get('ia-bookmarks')) {
+  customElements.define('ia-bookmarks', IABookmarks);
+}
diff --git a/src/plugins/search/search-results.js b/src/plugins/search/search-results.js
index 9d25c4254..1d6030bc1 100644
--- a/src/plugins/search/search-results.js
+++ b/src/plugins/search/search-results.js
@@ -386,4 +386,6 @@ export class IABookSearchResults extends LitElement {
     return [sharedStyles, buttonCSS, mainCSS];
   }
 }
-customElements.define('ia-book-search-results', IABookSearchResults);
+if (!customElements.get('ia-book-search-results')) {
+  customElements.define('ia-book-search-results', IABookSearchResults);
+}