diff --git a/FileLogger.cs b/FileLogger.cs
index 007d368..dd92128 100644
--- a/FileLogger.cs
+++ b/FileLogger.cs
@@ -15,7 +15,14 @@ namespace ln.logging
 
         private void openLogFile(string filename)
         {
-            fileStream = new FileStream(filename, FileMode.Append);
+            if (File.Exists(filename))
+            {
+                String oldfn = String.Format("{0}.old", filename);
+                if (File.Exists(oldfn))
+                    File.Delete(oldfn);
+                File.Move(filename, oldfn);
+            }
+            fileStream = new FileStream(filename, FileMode.Create);
             writer = new StreamWriter(fileStream);
         }