diff --git a/AM2RPortHelper/Program.cs b/AM2RPortHelper/Program.cs
index 0f6da03..8ff6e27 100644
--- a/AM2RPortHelper/Program.cs
+++ b/AM2RPortHelper/Program.cs
@@ -322,7 +322,7 @@ namespace AM2RPortHelper
             Directory.Delete(baseTempDirectory, true);
         }
 
-        static void LowercaseFolder(string directory)
+        private static void LowercaseFolder(string directory)
         {
             DirectoryInfo dir = new DirectoryInfo(directory);