diff --git a/www/js/lib/zimArchive.js b/www/js/lib/zimArchive.js
index 83e1a20b..9372fbd8 100644
--- a/www/js/lib/zimArchive.js
+++ b/www/js/lib/zimArchive.js
@@ -190,13 +190,7 @@ define(['zimfile', 'zimDirEntry', 'util', 'utf8'],
                 if (dirEntry.namespace < "A") return 1;
                 if (dirEntry.namespace > "A") return -1;
                 // We should now be in namespace A
-                if (dirEntry.title) { 
-                    return prefix <= dirEntry.title ? -1 : 1;
-                } else {
-                    // Some dirEntries (e.g. subtitles) have no title, but are still sorted in the A namespace,
-                    // so, like libzim, we have to use the url as a comparator [kiwix-js #440 #443]
-                    return prefix <= dirEntry.url ? -1 : 1;
-                }
+                return prefix <= dirEntry.getTitleOrUrl() ? -1 : 1;
             });
         }, true).then(function(firstIndex) {
             var dirEntries = [];
@@ -207,7 +201,7 @@ define(['zimfile', 'zimDirEntry', 'util', 'utf8'],
                         'nextStart': index
                     };
                 return that._file.dirEntryByTitleIndex(index).then(function(dirEntry) {
-                    var title = dirEntry.title ? dirEntry.title : dirEntry.url;
+                    var title = dirEntry.getTitleOrUrl();
                     if ((saveStartIndex === null || !title.indexOf(prefix)) && dirEntry.namespace === "A")
                         dirEntries.push(dirEntry);
                     return addDirEntries(index + 1);
diff --git a/www/js/lib/zimDirEntry.js b/www/js/lib/zimDirEntry.js
index 14685db7..974deb7e 100644
--- a/www/js/lib/zimDirEntry.js
+++ b/www/js/lib/zimDirEntry.js
@@ -108,7 +108,8 @@ define([], function() {
     };
 
     /**
-     * Defines a getter function that returns the URL if the title is empty
+     * Defines a function that returns the URL if the title is empty, as per the specification
+     * See https://wiki.openzim.org/wiki/ZIM_file_format#Directory_Entries
      * 
      * @returns {String} The dirEntry's title or, if empty, the dirEntry's (unescaped) URL   
      */