diff --git a/src/pyj/read_book/view.pyj b/src/pyj/read_book/view.pyj
index 701647f903..d513bb46ec 100644
--- a/src/pyj/read_book/view.pyj
+++ b/src/pyj/read_book/view.pyj
@@ -150,7 +150,7 @@ def margin_elem(sd, which, id, onclick, oncontextmenu):
     fsz = min(max(0, sz - 6), maximum_font_size())
     s = '; text-overflow: ellipsis; white-space: nowrap; overflow: hidden'
     ans = E.div(
-        style=f'height:{sz}px; overflow: hidden; font-size:{fsz}px; width:100%; padding: 0; display: flex; justify-content: space-between; align-items: center',
+        style=f'height:{sz}px; overflow: hidden; font-size:{fsz}px; width:100%; padding: 0; display: flex; justify-content: space-between; align-items: center; user-select: none',
         id=id,
         E.div(style='margin-right: 1.5em' + s), E.div(style=s), E.div(style='margin-left: 1.5em' + s)
     )
@@ -172,7 +172,7 @@ def side_margin_elem(self, sd, which):
         E.div(class_='arrow', style='order: 3', svgicon(f'caret-{which}', '100%', '100%')),
         E.div(style='order:1'), E.div(style='order:2', class_='not-arrow'), E.div(style='order:4'),
 
-        style='width:{}px;'.format(sd.get(f'margin_{which}', 20)),
+        style='width:{}px; user-select: none'.format(sd.get(f'margin_{which}', 20)),
         class_='book-side-margin', id=f'book-{which}-margin',
         onclick=self.side_margin_clicked.bind(None, which),
         oncontextmenu=self.margin_context_menu.bind(None, which),