diff --git a/KaraokePlayer/MainForm.cs b/KaraokePlayer/MainForm.cs
index e005a8b..0c957e5 100644
--- a/KaraokePlayer/MainForm.cs
+++ b/KaraokePlayer/MainForm.cs
@@ -79,7 +79,7 @@ namespace KaraokePlayer
         {
             Song file = (Song)materialListBox1.SelectedItem;
             currentSong = file;
-            if (file.Extension.ToLower() == "cdg")
+            if (file.Extension == ".cdg")
             {
                 currentPlayer = karaokeCDGPlayer;
                 karaokeCDGPlayer.Play(new Uri(Path.ChangeExtension(file.FullPath, ".mp3")));
@@ -87,7 +87,7 @@ namespace KaraokePlayer
                 karaokeMP4Player.Visible = false;
                 karaokeMP4Player.Stop();
             }
-            else if (file.Extension.ToLower() == "zip")
+            else if (file.Extension == ".zip")
             {
                 string playPath = null;
                 string extractPath = Path.Combine(Directory.GetCurrentDirectory(), "temp");