diff --git a/src/calibre/gui2/book_details.py b/src/calibre/gui2/book_details.py
index 3a4347da07..1db1a88a02 100644
--- a/src/calibre/gui2/book_details.py
+++ b/src/calibre/gui2/book_details.py
@@ -1333,8 +1333,14 @@ class BookDetails(DetailsLayout):  # {{{
             )
 
         def browse(url):
+            if url.startswith(DATA_DIR_NAME + '/') and self.last_data.get('book_id'):
+                base = get_gui().current_db.abspath(self.last_data['book_id'], index_is_id=True)
+                path = os.path.join(base, url)
+                qurl = QUrl.fromLocalFile(path)
+            else:
+                qurl = QUrl(url, QUrl.ParsingMode.TolerantMode)
             try:
-                safe_open_url(QUrl(url, QUrl.ParsingMode.TolerantMode))
+                safe_open_url(qurl)
             except Exception:
                 import traceback
                 traceback.print_exc()
@@ -1389,7 +1395,7 @@ class BookDetails(DetailsLayout):  # {{{
 
     def show_data(self, data):
         try:
-            self.last_data = {'title':data.title, 'authors':data.authors}
+            self.last_data = {'title':data.title, 'authors':data.authors, 'book_id': getattr(data, 'id', None)}
         except Exception:
             self.last_data = {}
         self.book_info.show_data(data)
diff --git a/src/calibre/gui2/comments_editor.py b/src/calibre/gui2/comments_editor.py
index fd19090127..22dd7c7699 100644
--- a/src/calibre/gui2/comments_editor.py
+++ b/src/calibre/gui2/comments_editor.py
@@ -1003,6 +1003,12 @@ class EditorWidget(QTextEdit, LineEditECM):  # {{{
             if a <= q <= b:
                 return cf
 
+    def open_link(self, link: str) -> None:
+        qurl = QUrl(link, QUrl.ParsingMode.TolerantMode)
+        if qurl.isRelative() and self.base_url:
+            qurl = QUrl.fromLocalFile(os.path.join(os.path.dirname(self.base_url.toLocalFile()), qurl.path()))
+        safe_open_url(qurl)
+
     def contextMenuEvent(self, ev):
         menu = QMenu(self)
         img_name = self.document().documentLayout().imageAt(QPointF(ev.pos()))
@@ -1033,7 +1039,7 @@ class EditorWidget(QTextEdit, LineEditECM):  # {{{
                 align_menu.addAction(QIcon.ic('trash.png'), _('Remove this image')).triggered.connect(partial(self.remove_image_at, c.position()))
         link_name = self.document().documentLayout().anchorAt(QPointF(ev.pos()))
         if link_name:
-            menu.addAction(QIcon.ic('insert-link.png'), _('Open link'), partial(safe_open_url, QUrl(link_name)))
+            menu.addAction(QIcon.ic('insert-link.png'), _('Open link'), partial(self.open_link, link_name))
         for ac in 'undo redo -- cut copy paste paste_and_match_style -- select_all'.split():
             if ac == '--':
                 menu.addSeparator()