diff --git a/src/library/entry.cr b/src/library/entry.cr
index 7e8d81d..ba4b84a 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -1,10 +1,9 @@
 class Entry
   property zip_path : String, book : Title, title : String,
-    size : String, pages : Int32, id : String, title_id : String,
-    encoded_path : String, encoded_title : String, mtime : Time,
-    err_msg : String?
+    size : String, pages : Int32, id : String, encoded_path : String,
+    encoded_title : String, mtime : Time, err_msg : String?
 
-  def initialize(@zip_path, @book, @title_id, storage)
+  def initialize(@zip_path, @book, storage)
     @encoded_path = URI.encode @zip_path
     @title = File.basename @zip_path, File.extname @zip_path
     @encoded_title = URI.encode @title
@@ -46,10 +45,11 @@ class Entry
 
   def to_json(json : JSON::Builder)
     json.object do
-      {% for str in ["zip_path", "title", "size", "id", "title_id",
+      {% for str in ["zip_path", "title", "size", "id",
                      "encoded_path", "encoded_title"] %}
         json.field {{str}}, @{{str.id}}
       {% end %}
+      json.field "title_id", @book.id
       json.field "display_name", @book.display_name @title
       json.field "cover_url", cover_url
       json.field "pages" { json.number @pages }
@@ -67,7 +67,7 @@ class Entry
 
   def cover_url
     return "#{Config.current.base_url}img/icon.png" if @err_msg
-    url = "#{Config.current.base_url}api/page/#{@title_id}/#{@id}/1"
+    url = "#{Config.current.base_url}api/page/#{@book.id}/#{@id}/1"
     TitleInfo.new @book.dir do |info|
       info_url = info.entry_cover_url[@title]?
       unless info_url.nil? || info_url.empty?
diff --git a/src/library/library.cr b/src/library/library.cr
index 405b933..a062105 100644
--- a/src/library/library.cr
+++ b/src/library/library.cr
@@ -128,7 +128,7 @@ class Library
       .each do |e|
         break if recently_added.size > 12
         last = recently_added.last?
-        if last && e[:entry].title_id == last[:entry].title_id &&
+        if last && e[:entry].book.id == last[:entry].book.id &&
            (e[:date_added] - last_date_added.not_nil!).duration < 1.day
           # A NamedTuple is immutable, so we have to cast it to a Hash first
           last_hash = last.to_h
diff --git a/src/library/title.cr b/src/library/title.cr
index f1e96dc..9ac8a72 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -34,7 +34,7 @@ class Title
         next
       end
       if [".zip", ".cbz", ".rar", ".cbr"].includes? File.extname path
-        entry = Entry.new path, self, @id, storage
+        entry = Entry.new path, self, storage
         @entries << entry if entry.pages > 0 || entry.err_msg
       end
     end
diff --git a/src/views/opds/title.xml.ecr b/src/views/opds/title.xml.ecr
index f5a3311..16ff3d0 100644
--- a/src/views/opds/title.xml.ecr
+++ b/src/views/opds/title.xml.ecr
@@ -28,10 +28,10 @@
       <link rel="http://opds-spec.org/image" href="<%= e.cover_url %>" />
       <link rel="http://opds-spec.org/image/thumbnail" href="<%= e.cover_url %>" />
 
-      <link rel="http://opds-spec.org/acquisition" href="<%= base_url %>opds/download/<%= e.title_id %>/<%= e.id %>" title="Read" type="<%= MIME.from_filename e.zip_path %>" />
+      <link rel="http://opds-spec.org/acquisition" href="<%= base_url %>opds/download/<%= e.book.id %>/<%= e.id %>" title="Read" type="<%= MIME.from_filename e.zip_path %>" />
 
-      <link type="text/html" rel="alternate" title="Read in Mango" href="<%= base_url %>reader/<%= e.title_id %>/<%= e.id %>" />
-      <link type="text/html" rel="alternate" title="Open in Mango" href="<%= base_url %>book/<%= e.title_id %>" />
+      <link type="text/html" rel="alternate" title="Read in Mango" href="<%= base_url %>reader/<%= e.book.id %>/<%= e.id %>" />
+      <link type="text/html" rel="alternate" title="Open in Mango" href="<%= base_url %>book/<%= e.book.id %>" />
     </entry>
   <% end %>