diff --git a/frontend/ui/widget/filechooser.lua b/frontend/ui/widget/filechooser.lua
index 9ca9bbd70..ea5bff7c9 100644
--- a/frontend/ui/widget/filechooser.lua
+++ b/frontend/ui/widget/filechooser.lua
@@ -158,13 +158,13 @@ function FileChooser:getListItem(f, filename, attributes, collate)
     }
     if collate then -- file
         if G_reader_settings:readSetting("show_file_in_bold") ~= false then
-            item.opened = DocSettings:hasSidecarFile(filename)
+            item.opened = DocSettings:hasSidecarFile(filename) and true or false
         end
         if collate == "type" then
             item.suffix = util.getFileNameSuffix(f)
         elseif collate == "percent_unopened_first" or collate == "percent_unopened_last" then
             local percent_finished
-            item.opened = DocSettings:hasSidecarFile(filename)
+            item.opened = DocSettings:hasSidecarFile(filename) and true or false
             if item.opened then
                 local doc_settings = DocSettings:open(filename)
                 percent_finished = doc_settings:readSetting("percent_finished")