diff --git a/src/pyj/book_list/book_details.pyj b/src/pyj/book_list/book_details.pyj
index 9f26b61ef4..47313c735b 100644
--- a/src/pyj/book_list/book_details.pyj
+++ b/src/pyj/book_list/book_details.pyj
@@ -403,10 +403,11 @@ def render_book(container_id, book_id):
         return
     metadata = book_metadata(book_id)
     set_title(c, metadata.title)
-    alt = _('{} by {}').format(metadata.title, metadata.authors.join(' & '))
+    authors = metadata.authors.join(' & ') if metadata.authors else _('Unknown')
+    alt = _('{} by {}').format(metadata.title, authors)
     imgdiv = E.div(
         E.img(
-            alt=alt, title=alt, data_title=metadata.title, data_authors=metadata.authors.join(' & '),
+            alt=alt, title=alt, data_title=metadata.title, data_authors=authors,
             style='border-radius: 20px; max-width: calc(100vw - 2em); max-height: calc(100vh - 4ex - {}); display: block; width:auto; height:auto; border-radius: 20px'.format(get_font_size('title')
         ))
     )
@@ -592,7 +593,7 @@ def search_internet(container_id):
     container = document.getElementById(container_id)
     create_top_bar(container, title=_('Search the internet'), action=back, icon='close')
     mi = book_metadata(render_book.book_id)
-    data = {'title':mi.title, 'author':mi.authors[0]}
+    data = {'title':mi.title, 'author':mi.authors[0] if mi.authors else _('Unknown')}
 
     def link_for(name, template):
         return E.a(name, class_='simple-link', href=url_for(template, data), target="_blank")
diff --git a/src/pyj/book_list/cover_grid.pyj b/src/pyj/book_list/cover_grid.pyj
index bfc61001f9..d7057b213d 100644
--- a/src/pyj/book_list/cover_grid.pyj
+++ b/src/pyj/book_list/cover_grid.pyj
@@ -60,7 +60,7 @@ def on_img_load(img, load_type):
         set_css(div, border='dashed 1px currentColor', border_radius=BORDER_RADIUS+'px')
 
 def create_item(book_id, metadata, create_image, show_book_details):
-    authors = metadata.authors.join(' & ')
+    authors = metadata.authors.join(' & ') if metadata.authors else _('Unknown')
     img = create_image(book_id, THUMBNAIL_MAX_WIDTH, THUMBNAIL_MAX_HEIGHT, on_img_load)
     img.setAttribute('alt', _('{} by {}').format(metadata.title, authors))
     img.dataset.title, img.dataset.authors = metadata.title, authors
diff --git a/src/pyj/book_list/details_list.pyj b/src/pyj/book_list/details_list.pyj
index b48f1343d4..64176b1c11 100644
--- a/src/pyj/book_list/details_list.pyj
+++ b/src/pyj/book_list/details_list.pyj
@@ -63,7 +63,7 @@ def on_img_load(img, load_type):
 
 
 def create_item(book_id, metadata, create_image, show_book_details):
-    authors = metadata.authors.join(' & ')
+    authors = metadata.authors.join(' & ') if metadata.authors else _('Unknown')
     img = create_image(book_id, THUMBNAIL_MAX_WIDTH, THUMBNAIL_MAX_HEIGHT, on_img_load)
     img.setAttribute('alt', _('{} by {}').format(metadata.title, authors))
     img.dataset.title, img.dataset.authors = metadata.title, authors
@@ -90,7 +90,7 @@ def create_item(book_id, metadata, create_image, show_book_details):
         class_='details-list-right',
             E.div(style='display:flex; justify-content: space-between; overflow: hidden',
             E.div(
-                E.b(metadata.title or _('Unknown')), E.br(), metadata.authors.join(' & '),
+                E.b(metadata.title or _('Unknown')), E.br(), authors,
             ),
             extra_data
         ),
diff --git a/src/pyj/book_list/home.pyj b/src/pyj/book_list/home.pyj
index 296c8e7dcc..f81a212b79 100644
--- a/src/pyj/book_list/home.pyj
+++ b/src/pyj/book_list/home.pyj
@@ -107,8 +107,9 @@ def show_recent_stage2(books):
         if username and to_sync.length < 10:
             lr = book.last_read[username_key(username)] or new Date(0)  # noqa: unused-local
             to_sync.push(v'[book.key, lr]')
+        authors = book.metadata.authors.join(' & ') if book.metadata.authors else _('Unknown')
         img = E.img(
-            alt=_('{} by {}').format(book.metadata.title, book.metadata.authors.join(' & '))
+            alt=_('{} by {}').format(book.metadata.title, authors)
         )
         img_id = ensure_id(img)
         images.appendChild(E.div(style='margin: 0 1em',
diff --git a/src/pyj/book_list/local_books.pyj b/src/pyj/book_list/local_books.pyj
index bbff33ea91..0de0fbeaf3 100644
--- a/src/pyj/book_list/local_books.pyj
+++ b/src/pyj/book_list/local_books.pyj
@@ -55,8 +55,9 @@ def create_image(book_idx, max_width, max_height, on_load):
         on_load(this, 'load')
     book = book_list_data.book_data[book_idx]
     if book?.metadata:
+        authors = book.metadata.authors.join(' & ') if book.metadata.authors else _('Unknown')
         img.setAttribute('alt', _('{} by {}').format(
-            book.metadata.title, book.metadata.authors.join(' & ')))
+            book.metadata.title, authors))
     if book?.cover_name:
         img_id = ensure_id(img, 'local-cover-')
         get_db().get_file(book, book.cover_name, show_cover.bind(img_id))