diff --git a/frontend/apps/reader/modules/readerbookmark.lua b/frontend/apps/reader/modules/readerbookmark.lua
index b0ae4fd59..238bf0c10 100644
--- a/frontend/apps/reader/modules/readerbookmark.lua
+++ b/frontend/apps/reader/modules/readerbookmark.lua
@@ -391,7 +391,8 @@ end
 function ReaderBookmark:isBookmarkSame(item1, item2)
     if item1.notes ~= item2.notes then return false end
     if self.ui.document.info.has_pages then
-        return item2.pos0 and item2.pos1 and item1.pos0.page == item2.pos0.page
+        return item1.pos0 and item1.pos1 and item2.pos0 and item2.pos1
+        and item1.pos0.page == item2.pos0.page
         and item1.pos0.x == item2.pos0.x and item1.pos0.y == item2.pos0.y
         and item1.pos1.x == item2.pos1.x and item1.pos1.y == item2.pos1.y
     else