 
           @embedBox.embedLinks.setLinks firstUrl
 
-          unless @previousURL is firstUrl
+          unless (@previousURL in firstUrl)
             @embedBox.embedUrl firstUrl?[0], {
               maxWidth: 525
             }, (embedData)=>

              @embedLinks?.linkList?.items?[0]?.setFavicon embedData.favicon_url

              @requestEmbedLock = off
              @previousURL = firstUrl
        else
          @requestEmbedLock = off
      ,50


    # saves the URL of the previous request to avoid
    # multiple embed calls for one URL
    @previousURL = ""

    # prevents multiple calls to embed.ly functionality
    # at the same time
