diff --git a/qtc-net-client-2/Services/UpdateService.cs b/qtc-net-client-2/Services/UpdateService.cs
index 5312eef..04a023b 100644
--- a/qtc-net-client-2/Services/UpdateService.cs
+++ b/qtc-net-client-2/Services/UpdateService.cs
@@ -68,6 +68,9 @@ namespace qtc_net_client_2.Services
 
             try
             {
+                // if bak file already exists, delete it
+                if (File.Exists($"/{updateInfo.ClientFileName}.bak")) File.Delete($"/{updateInfo.ClientFileName}.bak");
+
                 // move old client to backup file
                 File.Move($"./{updateInfo.ClientFileName}", $"{updateInfo.ClientFileName}.bak");